Gastrointestinal surgery for severe obesity: National Institutes of Health Consensus Development Conference Statement1 March

25-27,

1991

ABSTRACT

The

Development

National

Conference

Obesity brought together crinologists, psychiatrists, professionals

as well

treatment options severe obesity and of surgical

surgeons, nutritionists,

as the

for severe

to address:

obesity,

that

first

(1) patients

time

should

surgical program men, appropriate support,

(2)

considered

gastric

a multidisciplinary nutritional expertise, substantially of management veillance after consensus 1992:55:6

or bypass

(3) patients be selected

with

setting

and surgical

panel’s 1 5S-9S.

appropriate

procedures

support

statement

follows.

medical full text

Am

J

use

not

Nutr

In a 1985

National

the

including

Institutes

health

increased

risk

hypertension),

dyslipidemia, prevalences socioeconomic

define

morbidity to the

overweight

.4,n

male.

The

mass BMI

gallbladder

index

(BMI):

associated

Persons

J (‘fin Nuir

over 40 kg/m2. A BMI 100 pounds overweight

at the highest

1992:55:61

55-95.

risk ofmorbidity Printed

in USA.

severe

obesity.

to significant

comorbid

abnormalities

and

In addition, frequently

These

facts

care for those

the

undesirable

asseveral

significant psyare experienced

lend

seeking

side

urgency

to the

relieffrom

have

have

volume,

gastric

of weight loss both food aversion

determined

with

led to reports

effects

ofthis

In the past

procedures

in gastric

certainty.

effects

operation,

10 to 15 years,

been

developed;

bypass,

and

with

these

other

newer

pro-

procedures,

and malabsorption, Refinements

of results

Institute

of Diabetes

of Medical

superior

a consensus

and

is to

general

medicine,

psychiatry,

(ki-

Digestive

Applications development

1991. After 2 days of presentations consensus panel representing the

have

in such to those

pro-

seen

with

conference

and

Kidney

Disease

of the NIH March

25-27,

by experts in the field, a professional fields of surgery,

gastroenterology,

endocrinology,

and

of Research

nutrition, including

epidemiology,

representatives

from

lowest 4 million another

For making bibliographic reference to the consensus statement from this conference, it is suggested that the following format be used, with or without source abbreviations, but without author attribution: Gastrointestinal Surgery for Severe Obesity. NIH Consens Dcv ConfConsens Statement 199 1 March 25-27; 9(1).

of 40 kg/m2 is for an average and

disorders. problems

of surgical

convened

types

[weight

and

been

National

obesity means with

types reduction

and the Office

dis-

ofselected impairment.

is between 20 and 25 kg/m2. Approximately have BMI’s between 35 and 40 kg/m2, BMI’s to

as

(especially

mortality accompanying of overweight. A simple

(meters)2].

1 .5 million have roughly equivalent adult

mellitus,

obesity

the earlier operation; however, side effects sometimes do occur, and in spite of weight loss, ideal body weight is rarely attained. The time has come to evaluate the objective evidence for these new surgical therapies. To resolve questions relating to surgery for severe obesity, the

con-

established

disease

mortality ratios and psychosocial

is by the body

lograms)/height mortality Americans

diabetes

consensus

were

cardiovascular

and

and degree

(NIH)

of obesity

for

ease, increased of cancer, and Risk for proportional

ofHealth

implications

part

of metabolic

rational

highlighted

cedures

Introduction

ference,

with

cedures. Mechanisms which may include

surof the

C/in

a term

severe

by surgical procedures. obesity is unknown, and

its use has all but disappeared.

other

and

for all aspects

and (5) lifelong is a necessity. The

obesity,” with

condition.

ference

and

surgical, psychiatric, and be performed by a surgeon

adequate

assessment, therapy

be ac-

severe Patients

A 1978 NIH consensus conference on surgery for obesity considered primarily intestinal (jejunoileal) bypass, which exerts its weight-loss effects through malabsorption, decreased food intake, and possibly other mechanisms. This operation was shown to be effective in some reported series ofcases, but in many patients it was accompanied by serious complications. The 1978 con-

who are candidates for surcarefully after evaluation by

the

with

by persons

effort to provide

regiand

with

in large

form

cardiopulmonary and economic

of this

could

patients

“clinically obesity.”

for treatment basis ofsevere

is due

in the

serious

obesity

procedures

motivated

which

chosocial

in a non-

of a dietary modification

as having to “morbid

therapy directed to it, therefore, is not available. This nevertheless, is accompanied by a reduction in life cx-

sociations

and prethe panel

for severe

is preferred

pectancy,

for future

for treatment

team with medical, (4) the operation

in a clinical

therapy

be categorized

that

specific disorder,

for risks

of these therapies. and discussion by

components behavioral

and

experienced

working

seeking

restrictive

risks, should

nonsurgical

the need

can

are potential candidates The ultimate biologic

endocare

health

the evidence their findings,

be considered

well-informed

ceptable operative gical procedures

and

weighed Among

with integrated exercise, and

for

for Severe

the

evaluation by experts

the audience, a consensus panel pared their consensus statement. for the

Consensus

Surgery

obesity, the surgical treatments for selection, the efficacy and

on and epidemiological 2 days of presentations

recommended

of Health

gastroenterologists, and other

public

for severe the criteria

treatments

research Following

Institutes

on Gastrointestinal

mortality

© 1992 American

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Society

for Clinical

Nutrition

6 1 5S

NIH

6 1 6S medical

literature

agreed

on answers

What

are the nonsurgical

obesity

and the public,

their

and

to the

CONSENSUS

considered

questions

that

CONFERENCE

the evidence

and

follow.

treatment consequences?

and

STATEMENT frequent

ognized stantial

options

for

sity

approaches

include

diets,

various

behavioral

to treatment

combinations

ofcinically of low-

modification,

exercise,

In addition to weight reduction tom such as hypertension, dyslipidemia,

agents. can

be treated

by usual

medical

severe

or very

obe-

low-calorie

and pharmacologic regimens, comorbid facand diabetes mellitus

methods.

Published

studies

of

approaches to the treatment of obesity include few reports or indications of efficacy in persons with clinically severe obesity. The potential efficacy of these approaches in persons with this degree of obesity, therefore, must be inferred from evidence of their efficacy in less obese persons. Nonsurgical treatment ofclinically severe obesity aims to crcate a caloric deficit sufficient to result in both permanent weight loss and reduction ofweight-related risk factors or comorbidity. The specific amount oftargeted weight loss is defined on a caseby-case basis and does not necessarily require reduction to ideal body weight. Very low-calorie diets (VLCD’s) have been widely publicized as having dramatic success in the treatment of clinically severe obesity. Typically, these diets contain 400 to 800 kilocalories per day with increased protein and minimal fat in a solid or liquid form. Significant weight reduction, for example 20 kg over 12 weeks, can be expected. However, in the absence of successful behavior modification, most patients regain their lost weight within 1 year. Thus, although VLCD’s used under close medical

medical

supervision

often

are

effective

in short-term

treatment

these diets alone

generally have not permanent weight loss. Combining a VLCD with intensive behavioral modification may be more effective than a VLCD alone for treating the severely obese patient. Although data on the use of this approach are few, some evidence suggests that initial treatment with a VLCD followed by intensive behavioral modification may result in sustained weight loss in highly motivated patients with clinically severe ofclinically severe obesity, been successful for achieving

obesity. Behavioral

surveillance.

Recent

studies

and

decrease

the motivation

for further

medical

acceptably,

a major

treatment restriction,

drawback

What are selection?

the surgical

A number

to the

nonsurgical

although

evidence

oflong-term

ommended

exercise

as a component

in promoting

ofweight-loss

and sustaining

efficacy

clinically activity

programs,

weight

treatments

or

because

practice

criteria

have of

in the early

the experimental

and

and

1990’s

advanced

and

have

Experience

with drug

disappointing.

therapy

Although

for clinically

severe

pharmacologic

studies

externally

reinforced

Gastric bypass proximal gastric bowel of varying Choosing preference

to prevent

disruption

or dilation.

procedures (see Fig 2) involve constructing a pouch whose outlet is a Y-shaped limb of small lengths (Roux-en-Y gastric bypass).

between these and consideration

procedures involves the surgeon’s of the patient’s eating habits. The

of

has

with

an-

orexigenic drugs suggest short-term benefit, prolonged and sustamed weight loss has not been proved with these agents. Drugs such as amphetamines and thyroid derivatives are unsafe and unapproved. Medical

are usually rhythmias

avoided

complications

treatable.

of rapid

weight

loss

may

occur

and

abnormalities and cardiac axduring administration of VLCD’s generally can be or corrected by the inclusion of high-quality protein

Electrolyte

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beyond

Vertical banded gastroplasty (see Fig 1) and related techniques consist of constructing a small pouch with a restricted outlet along the lesser curvature of the stomach. The outlet may be

been

obesity

as

procedures

stage.

established. been

discarded

Two

of

the role

is

for

been tried complications.

severe is rec-

loss has never

approach

body

of operations

inefficacious dominate

reduced

is a therapeutic

this more conservative approach in persons with obesity is lacking. Although increased physical

therapy.

weight in most patients. The not be excluded that the highly motivated patient can achieve sustained weight reduction by a combination ofsupervised low-calorie diets and prolonged, intensive behavior modification therapy. failure to maintain possibility should

the assumption that habitual eating haviors must be relearned to promote Behavioral ofcaloric

rec-

Limited success has been achieved by various techniques that include medically supervised dieting and intensive behavior modification. During such a treatment program, comorbidity factors such as hypertension, dyslipidemia, and diabetes mellitus can be treated by conventional medical therapy in the patient with clinically severe obesity. Although weight may be reduced

approach based on and physical activity belong-term weight change. also can be combined with a lesser degree

modification

have

may be associated with a subAlthough there are no specific

complications of behavior therapy, failure to achieve sustained weight reduction may heighten the patient’s sense of personal

severe

failure Nonsurgical

physician

that rapid weight loss incidence of gallstones.

FIG

I . Vertical

banded

gastroplasty.

NIH

CONSENSUS

CONFERENCE

6 1 7S

STATEMENT

sleep apnea,

Pickwickian

myopathy)

or severe

syndrome,

diabetes

and obesity-related

mellitus.

Other

cardio-

possible

indications

for patients with BMI’s between 35 and 40 include obesity-induced physica/problems interfering with lifestyle (e.g., joint disease treatable but for the obesity, or body size problems precluding

or severely

interfering

with

employment,

family

function,

and ambulation). Children and adolescents have not been sufficiently studied to allow a recommendation for surgery for them even in the face of obesity associated with BMI over 40.

What are the for obesity?

efficacy

and

risks

of surgical

treatments

Issues ofefficacy and risk in bariatric surgical procedures must be viewed in light of the fact that severe obesity is a chronic intractable

FIG 2. Roux-en-Y

gastric

bypass.

must somewhat greater must be balanced

weight

against

disorder;

any

therapeutic

program

must,

therefore,

be lifelong. While definitive therapy for severe obesity is not available, the surgical procedures in use can induce substantial weight loss, and this, in turn, may ameliorate comorbid conditions. Since short- and intermediate-term effects observed in several studies may relate to long-term benefits, further application and investigation ofthese operations arejustified. It must be kept in mind, however, that long-term results are of critical importance and

loss after the gastric bypass procedure its higher risk ofnutritional deficiencies,

especially of micronutrients. Biliary-pancreatic bypass

includes a gastric restriction and dijuice into the distal ileum. Experience in the United States is limited.

be delineated.

Ofspecial

note,

many

patient

to date are not representative ofthe distribution and cultural factors, and socioeconomic status verely obese population. Efficacy

with the procedure

Weight loss. The two major types of present operations for severe obesity are vertical banded gastroplasty and Roux-en-Y gastric bypass. The success rate for weight loss has been reported to be slightly higher with the Roux-en-Y operation. Substantial weight loss generally occurs, with the weight nadir occurring in

selection

These surgical procedures are major operations with shortand long-term complications, some ofwhich remain to be completely elucidated. There are insufficient data on which to base recommendations for patient selection using objective clinical features alone. However, while data accumulate, it may be possible in certain cases to consider surgery on the basis of limited information from the uncontrolled or short-term followup studies available. A decision to use surgery requires assessing the risk-benefit ratio in each case. Those patients judged by expe-

rienced

clinicians

to have

a low probability

ofsuccess

with

non-

in established weight control programs or reluctance by the patient to enter such a program, may be considered for surgery. A gastric restrictive or bypass procedure should be considered only for well-informed and motivated patients with acceptable operative risks. The patient should be able to participate in treatment and long-term followup. Patients whose BMI exceeds 40 are potential candidates for surgery if they strongly desire substantial weight loss, because obesity severely impairs the quality of their lives. They must clearly and realistically understand how their lives may change after operation. In certain instances less severely obese patients (with BMI’s surgical

measures,

between 35 and in this category

such

as demonstrated

for

40) also may be considered are patients with high-risk

as life-threatening

cardiopulmonary

example

by failures

for surgery.

comorbid problems

Included

conditions (e.g. severe

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18 to 24 months.

treatmentsfor

studied

of race, ethnic among the se-

verts bile and pancreatic

Patient

ofsurgical

cohorts

Some

regain

obesity

of weight

is common

by 2 to 5

after operation. A third operation, biliopancreatic bypass, about which there are only limited data, also has been reported to produce weight loss but with a higher frequency of metabolic years

complications.

Comorbid conditions. Weight reduction surgery has been reto improve several comorbid conditions such as sleep apnea and obesity-associated hypoventilation, glucose intolerance, frank diabetes mellitus, hypertension, and serum lipid abnormalities. Whether beneficial effects in the various metabolic ported

disorders

are

damage

heart

(e.g.

maintained renal

long

disease,

enough

stroke,

to

prevent

myocardial

end-organ

infarction

and

failure)

is not known. Psychosocial effects. Many patients report improvement in mood and other aspects of psychosocial functioning after these operative procedures. The degree to which these improvements are sustained is unknown. Risk evaluating Available

the risks in the surgical treatment ofobesity involves both perioperative and long-term complications. published series report that the immediate operative

mortality

rate

Assessing

en-Y

gastric

for both

bypass

vertical

is relatively

banded

gastroplasty

low. On the other

and

hand,

Roux-

mor-

618S

NIH

bidity

in the

dehiscence,

early

postoperative

leaks

marginal

from

ulcers,

bophlebitis

various

in the

period,

staple

line may

dilation,

obstruction),

persistent

kind

and deep throm-

be as high

as

or failure

10 percent

or

weight.

Moreover,

by a decision

of program

therapy

other problems may are pouch and distal (with or without stomal

to lose

STATEMENT

be followed

stenosis,

period, These

vomiting

cholecystitis,

CONFERENCE

infections,

stomal

problems,

more. In the later postoperative arise and may require reoperation. esophageal

i.e. wound

breakdown,

pulmonary

aggregate,

CONSENSUS

for nonsurgical

or with

if significant

therapy

a different

in a different

therapist,

comorbidities

do

not

for

exist,

no

further

or for surgical

therapy. Patients who are candidates viewed during this conference evaluation

for the surgical should be selected

by a multidisciplinary

surgical,

psychiatric,

and

team

nutritional

with

procedures carefully

access

expertise.

reafter

to medical,

Patients

should

mortality and morbidity rates with reoperation are higher than those of primary operations. In the long term, micronutrient deficiencies, particularly of vitamin B12, folate, and iron, are common after gastric bypass and must be sought and treated. Another potential result of this

advantages of each. The need for lifelong medical surveillance after surgical therapy should be made clear. With all of these considerations, the patient should be helped to arrive at a fully

operation

is the so-called

informed,

acterized

by gastrointestinal

casionally,

these

“dumping

symptoms

may

because

reduction uncertain weight

as many

and not

measures and may be troublesome Many data suggest that deficient with it a high risk of fetal damage concern

syndrome,”

distress

which

other

respond

is char-

symptoms. to conservative

ofpatients

having

weight

micro-

or macronutrient

deficiency,

or other

met-

abolic sequelae ofthese procedures, secure birth control methods should be provided for these patients during this period of weight loss. They should be informed that maternal malnutrition may impair

after

normal

these

clinical

fetal development.

surgical

care

procedures

team.

The

Women

need

increased

who

special

become

pregnant

attention

nutritional

from

the

requirements

for

energy, protein, need for weight

and specific micronutrients as well as the normal gain during pregnancy must be emphasized as part of the obstetrical management of these patients. Quality-of-life

considerations

in patients

undergoing

surgical

treatment for obesity must be considered, as there must be reorientation and adjustment to the side effects ofsurgery and the effect ofa changing body image. Euphoria can be seen in patients during the early postoperative period. Some patients, however, may experience significant late postoperative depression. Some patients have depressive symptoms that are not improved by surgically-induced

What

weight

specific

treatment Decisions clinically

loss.

recommendations

of severe on severe

what obesity

can

be made

for the

obesity? therapy

to patients

to recommend

should

depend

on their

wishes

with for out-

comes, on the physician’s judgment of the urgency of the need for therapy, and on the physician’sjudgment ofpossible options for therapy and their probable efficacy. Patients seeking therapy for the first time should be evaluated by a knowledgeable physician and provided with sufficient information on which to make a reasonable choice for therapy. In most cases, patients should first be considered for treatment in a nonsurgical program with integrated components ofa dietary regimen, appropriate exercise, and behavioral support and modification.

Possible

comorbidities

such

as hypertension

and

diabetes should be sought and treated ifnot already under treatment. The desired outcomes may vary among patients and indude such indices as a gain in the quality of life as judged by the patient, reduction ofhypertension, and amelioration of glucose intolerance. Ajudgment offailed nonsurgical therapy should

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tolerate

surgery

and

decision

for surgical of the

with the physician

options

independent

A decision

with with

to explore

treatment

assessment

surgery are women ofchildbearing age. In view of the frequency and effects on fetal development of rapid loss,

unconsidered

Oc-

to the patient. nutrition in pregnancy carries or loss. This is of particular

as 80 percent

have an opportunity

that

excessive

extent

to which

of the compliance imen,

and

that

of the

be reached

the

patient

risk and

dis-

only

will

after

be able

to comply

to

adequately

There must be full discussion outcome of the surgery, of the

it will eliminate

the patient’s

will be needed

possible

and

his or her therapy.

should

the postoperative regimen. the patient of the probable

probable

advantages

concerning

therapy

probability

without

the

any previously

problems,

in the postoperative

complications

from

the

reg-

surgery,

both

short- and long-term. Women with reproductive potential would be well advised to avoid pregnancy until weight has stabilized postoperatively and potential micronutrient deficiencies have been identified and treated. The operation should be carried out by a surgeon substantially experienced with the appropriate procedures and working in a clinical setting with adequate support for all aspects of perioperative tional

management counseling,

and and

assessment. surveillance

Postoperative should continue

care, for

nutrian in-

definitely long period. The surveillance should include the monitoring of indices of inadequate nutrition and of amelioration

of any preoperative disorders such as diabetes, hypertension, and dyslipidemia. The monitoring should include not only indices of macronutrients but also of mineral and vitamin nutrition. What are the research, and

future directions epidemiological

for basic evaluation

science, clinical of therapy?

The panel recognized the need to develop safe and effective means to treat patients with clinically severe obesity. In the view ofthe panel, none ofthe available therapies, including surgery, has been adequately evaluated. For this reason, it is recommended that centers be developed that can manage patients with clinically

severe

at the same tigations

with

involve a team as epidemiology, enterology,

obesity,

time,

using

can enter

long-term

that

a multidisciplinary

these

patients

followup.

includes nutrition,

The

approach,

into controlled research

and,

inves-

will

need

to

professionals trained in fields such surgery, general medicine, gastro-

cardiovascular-pulmonary

medicine,

psychiatry,

and

endocrinology. Only if in-depth investigations are carried out over long periods will needed information be obtained to care for obese patients more effectively in the future. A series of issues arose during the conference that need additional investigation. These issues include the following: 1 The balance of efficacy and risk between surgical treatment and nontreatment or alternative treatments of severe obesity .

is difficult

to evaluate

are studies

that

with

use well-defined

available

groups

information.

of subjects

Lacking

and stan-

NIH dard

protocols,

comes. sufficiently ical trials 2.

with

adequate

Nevertheless, encouraging that address

procedures

are

A better

vocabulary

power

the current

clearly outcomes.

can

of any 4.

serve form

Various

terms

related These

and

The

and

were

risks

of surgical (ie,

6.

are

of

altered

of

enhanced

produces food

metabolism)

deserve

effects

therapy

of surgical fetuses after

and such

statistical more need

by these

treatment whether

7. One case

were

must of surgical

assessments

effective

of mothers

efficacy

The present of comorbidity

compare

for women

8.

is urgently

of outcomes.

alternate and

forms evaluated.

of weight-reduction Specifically,

group ment

to get

be determined. results

best

to maintain

weight

re-

the

identified:

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therapy.

therapy

needs

long-term exploration. long-term

drug

further

therapy Especially safety, and

in combination.

in evaluating therapy

the current

is the

practice to the

lack

reports

levels

approach

is to compare same patient’s

oflong-term

effects

for evaluating

of morbidity

and

surgical

mortality

of

of standards

for

postoperative own preop-

Although this approach may give some on short-term effects of surgical therapy, for evaluation

socioecode-

of drugs

in surgical

An alternative

their

psychologist,

approach.

how

drug

series

in various

on

and

key problems

erative status. information

proce-

age, ethnicity, fat distribution.

be-

populations

clinical

for pharmacologic

ofthe

comparison. indicators

whereby

surgical

be defined

it is safe

operations

to be developed

needs

should

gender, and

reporting

for clearer

In addition,

of mechanisms

reduced

of overweight

evaluation. The possibility that can be used successfully deserves important are efficacy of therapy,

obesity.

nutrients,

on

for

exercise

is a need to determine that are most effective

of physician,

behavioral

is needed

havior therapy, c. The potential

com-

of obesity.

treatment

Research

subgroups roles

techniques and

duction for a long term, with clarification of the roles of reduced caloric intake and increased energy expenditure (e.g., exercise). Consideration should be given to use of combined approaches, for example, low-calorie diets, be-

effects

definition

various

insufficient of surgical

veloping

following

in the

is required

for severe

surgical

is needed

factors

pregnant

therapy

therapy

intake,

subgroups stratified for nomic status, comorbidity,

needed

dietitian

maintenance,

for better

malabsorption

investigation

dures. c. The effects

Better

and b.

for

complications

identified

whereby

decreased

comorbidity

e.

the

investigation.

Further

The

to define

long-term

weight

in eating

and

terms

be compared

long-term

issues

reduction

further

should

loss,

mechanisms

aversion,

d.

obesity

behavioral

changes

needed

communication

the

effective

long-term

haviors is needed. Further, there the types of behavioral strategies

especially

ofsevere

to evaluate

in secondary

specific

weight

b.

weight

of more

producing

are

dinsurgical

critically

improve

history

procedures

rates,

the efficacy a.

a. Development

out-

series

of therapy.

improvement

5. Several

are

to obesity, will

as a baseline

surgical

plication

case

in treating

nomenclature

between investigators. 3. A definition ofthe natural that

long-term

from

6 1 9S

STATEMENT

in order. and

defining

to define

reports

CONFERENCE

to indicate that well-organized the critical issues surrounding

now

to define

CONSENSUS

and

useful it is

of survival.

therapy in the

is to

surgical

with an appropriate comparison group. The establishofa meaningful comparison group presents a challenge

to future research. Evaluation of the psychosocial changes that occur during weight reduction is needed. Standardized, reliable, and valid questionnaires and structured interviews should be developed to evaluate the patient’s expectations about changes and the psychosocial changes they actually experience during weight loss and maintenance.