What is the GI tract?
The gastrointestinal (GI) tract
is the tube from the mouth to the rectum. The GI tract includes the
esophagus, stomach, duodenum, liver, pancreas, small intestine (also
known as jejunum and ileum), large intestine (also known as the
colon) and rectum.
When we chew and swallow food, it
travels from the mouth to the stomach by moving through the
esophagus. Once the food is in the stomach, the food is partially
digested by the stomach acids and the movement in the stomach. The
stomach empties the partially digested food into the duodenum. In
the duodenum, the food is mixed with other digestive juices from the
pancreas and liver. The liver provides the digestive juice, bile and
the pancreas provides digestive pancreatic enzymes. Together, these
digestive juices complete the breakdown of the foods we eat.
From the duodenum, the digested
food moves into the small intestine for more digestion and
absorption. The major role of the small intestine is to absorb
nutrients from the food. Once the nutrients are absorbed, the
remaining liquid is passed into the large intestine. The major role
of the large intestine is to remove the extra water and to form
stool. The large intestine moves the stool to the rectum where it is
eliminated.
The gastrointestinal tract is a
very long muscular tube. It works together with the other organs to
complete the digestive process. The small intestine is a very long,
coiled tube. It is measured to be approximately 10-12 feet in
children and 20-25 feet in adults. The large intestine is also a
long tube which measures approximately 3 feet in children and 6-9
feet in adults.
What is Short Bowel Syndrome?
Short bowel syndrome is a general
term referring to the loss of absorptive function of the intestinal
tract. This results in malabsorption, diarrhea, and malnutrition. So
basically, the small intestine and large intestine do not work
properly. The small intestine is the most important GI
tract organ related to the development of this condition.
There are a variety of causes of
short bowel syndrome. The causes can be placed into two broad
categories; Surgical/Mechanical causes and Functional disorders.
Surgical or mechanical causes are the most common. It often occurs
because a doctor has to operate and remove segments of the
intestine.
From Feldman:
Sleisenger & Fordtran’s Gastroentestinal and Liver Disease; 7th
Edition; Figure 92-1, page 1808; 2002, Elsiever
The second category is functional
disorders. Functional disorders are problems that arise with the
intestines that prevent it from digesting, absorbing and moving food
through the intestinal tract. In some cases, patients can have both
surgical/mechanical and functional disorders causing short bowel
syndrome.
In some cases, short bowel
syndrome is temporary. Somehow, the remaining intestine has the
ability to adapt to the short bowel syndrome. The remaining small
bowel does more work than before and is able to make up for the
shorter length of small bowel. Successful adaptation is when a
patient can once again digests and absorb all nutrients through
their gastrointestinal tract. Adaptation starts very soon after the
onset of short bowel syndrome can take several years before it is
complete. The potential to adapt depends on a number of factors such
as health of patient, age of patient, length of remaining intestine,
presence or length of colon, and presence or absence of disease in
remaining intestine. Your doctor will advise you on the potential
of your intestine to adapt.
Unfortunately, there will be
patients who do not adapt from short bowel syndrome. Those patients
will require total parenteral nutrition (TPN) for the remainder of
their lives to prevent malnutrition and death. When a patient’s
intestine does not adapt, it is labeled as intestinal failure.
Total Parenteral
Nutrition (TPN)
Total parenteral nutrition (TPN)
is a liquid form of calories and nutrients given into a large vein.
TPN has been a life-saving option for patients who developed short
bowel syndrome and intestinal failure. TPN was invented in the late
1960’s and prior to the invention, all patients with short bowel
syndrome died of malnutrition. After years of formulation and
experience, TPN is a safe and effective way to provide
life-sustaining nutrients to patients who cannot absorb these
calories and nutrients from the gastrointestinal tract. Specialized
teams of medical professionals including doctors, nurses and
pharmacists work closely with patients on TPN to ensure all caloric,
fluid, and electrolyte needs are met in the safest manner.
There are limitations associated
with TPN. First, the patient must have long-term central venous
access. Most often, this is provided through a surgically placed
catheter also known as a central venous catheter (CVC). The
catheter is placed into one of the large veins in the chest. These
catheters require special care to prevent problems. Secondly, the
patient needs to have special equipment and supplies for
administration of the TPN. Thirdly, specialized medical care and
monitoring is required to make sure the TPN administration is safe.
There are also risks associated
with TPN. The risks of complications vary from patient to patient
and cannot be predicted. Some of these complications can be
life-threatening and require immediate medical attention. The major
complications are liver disease, central venous catheter (CVC)
infections, loss of CVC sites and major fluid and electrolyte
imbalances. Even with the limitations and risks, 80% or more of all
patients on TPN do well with few or no complications.
The risks of liver disease, CVC
infections and fluid & electrolyte imbalances are explained in
detail below:
1. Liver disease can be
associated with the administration of TPN. The cause of liver
disease is unknown. Some patients, particularly the very young
patient appears to be more likely to develop liver disease. It can
occur any time after the start of TPN therapy. While the causes are
unknown, there are several theories as to why patients may develop
liver disease. One theory is that the nutrients are delivered to the
body first and not to the intestine and liver. This in some way
alters the liver reaction to the nutrients leading to disease. A few
other theories include a loss of beneficial hormones given to the
liver when nutrients are delivered through the gastrointestinal
tract, possibly there are increases in bacteria that reach the liver
when nutrients are delivered through TPN, or that there is altered
blood flow to the liver related to the short bowel syndrome. In
truth, the cause may be unique to each patient and may represent a
combination of event. If patients develop progressive liver disease
on TPN and cannot come off of TPN (that is, their intestine does not
adapt), then they may develop end-stage liver disease or
cirrhosis. This condition is very severe and will result in
death without transplantation.
2. Vascular access complications
are the next most common complication associated with TPN therapy.
Multiple, recurrent infections of the central venous catheter
can result in removal of the central venous catheter and can lead to
severe, life-threatening infections. Doctors become very concerned
when patients must have several central venous catheters removed due
to infection, have infections with germs that are resistant to
antibiotics, have infections with yeast, or have infections that are
life-threatening. For unknown reasons, some patients appear more
susceptible to these infections than others. In addition, a huge
concern is the loss of central venous access sites. Adults
generally have 6-8 standard venous access sites and children have
4-6 standard central venous access sites. When patient clot veins so
that a catheter cannot be replaced in that vein, it is considered
permanently lost. If a patient has more than half of their potential
access sites removed, the medical team will become concerned over
the long-term ability to maintain catheters to deliver TPN.
There are other significant
complications that can be associated with TPN therapy. Patients can
become dehydrated or develop renal failure. Patients may require a
lot of medical care and frequent hospitalizations. Furthermore, the
risk of death is slightly higher for patients on TPN than that of
the general populations. The outcomes for an individual patient
cannot be predicted.
Patients with intestinal disease
or injury who are doing well on TPN are NOT candidates for
intestinal transplantation at this time. To be a candidate for an
intestinal transplantation:
-
Patients must have intestinal failure whereby
their remaining intestine is not expected to adapt
AND
-
Patients must have developed one or more
life-threatening complications related to TPN as outlined above.
It is only when the risks
from TPN exceed those of transplantation, is intestinal
transplantation considered.
The type of intestinal transplant
offered to a patient depends on the individual patient needs. There
are essentially 4 types of transplants involving the intestine.
-
The first is the isolated intestinal
transplant. This type of transplant consists of the small
bowel (jejunum and ileum) and is given to patients who have
normal liver function or a liver with early/reversible liver
disease and meet the criteria for intestinal transplantation.
-
The second type of transplant is the combined
liver and intestinal transplant. This consists of two organs
– the liver plus the entire small intestine together as one
group. It is given to patients with irreversible liver disease
and intestinal failure.
-
The third type of transplant is the
multivisceral transplant. This transplant includes the
liver, stomach, duodenum, pancreas, and small bowel. It is
reserved for patients who have organ failure involving the
liver, pancreas, and intestine or for patients with diffuse
diseases of their intestines (such as Gardner’s Syndrome,
intestinal polyposis, or motility disorders such as
pseudo-obstruction) associated with liver disease.
-
The fourth option is a modification of the
multivisceral transplant called the modified multivisceral
transplant in which the liver is not included and the
stomach may or may not be included. Again, the organs
transplanted are tailored to the patients needs.
The process of deciding if
intestinal transplantation is a treatment option for a patient
starts with the referral to a transplant team that specializes in
these types of transplants. Usually, a patient’s primary physician,
gastroenterologist, or surgeon will contact the transplant center
directly and provide access to the patient’s medical records and
history. Patients can refer themselves directly without going
through their primary physician however, as an important aspect of
the assessment is the patient’s past medical history, contact with
the referring physicians is recommended.
Referrals should be directed to:
Douglas G. Farmer, MD.
Director, Intestinal Transplant Program
Dumont-UCLA Transplant Center
Box 957054
Room 77-120 CHS
Los Angeles, California, USA 90095-7054
310-794-6487 office
310-825-5381 office
310-267-0392 fax
dgfarmer@mednet.ucla.edu
http://healthcare.mednet.ucla.edu/transplant/intestinalhome
INTESTINAL TRANSPLANT PROGRAM AT
THE DUMONT-UCLA TRANSPLANT CENTER
The Intestinal Transplant Program at UCLA is one of the oldest and
largest of its kind in the world. Initiated in 1991 by Drs Ronald
W. Busuttil and Douglas G. Farmer, it has developed
through the expertise and experience of the liver transplant program
into one of the most experienced intestinal transplant programs in
the county. The program meets the needs of adults and children with
intestinal and liver diseases by providing all types of transplants
involving the intestine as well as specialized medical care in the
fields of short bowel syndrome, intestinal rehabilitation,
gastrointestinal surgery, and total parenteral nutrition. The
program is the only one of its kind specializing in intestinal
transplantation in the Western USA. The evaluation and transplant
volume is one of the largest in the world. UCLA is the fifth program
in the USA to be certified by the Centers for Medicare and
Medicaid Services (CMS;
www.cms.hhs.gov ) in the Department of Health and Human Services
(DHHS). UCLA is an active participant in the Intestinal
Transplant Registry (www.intestinaltransplant.org).
The transplant center is located within the UCLA Medical Center in
Westwood, California just off the 405 Freeway and Wilshire
Boulevard. Please see map for directions.
Once the referral process is
complete, the patient will undergo a comprehensive,
multidisciplinary evaluation for transplantation. This process
usually requires 3 to 5 days in the hospital but can take place over
several weeks as an outpatient. The evaluation provides a
comprehensive assessment of a patient’s medical condition using a
multidisciplinary approach that includes surgeons,
gastroenterologist, hepatologist, nutritionist, TPN specialists,
transplant nurse coordinators as well as many other sub-specialists.
During the evaluation, patients will be assessed for the degree of
intestinal failure and liver disease. A complete assessment as to
the potential for bowel adaptation will be made as well as the
current nutritional status of the patient. A detailed analysis of
the TPN formulation and feeding regimen will be made. Radiographic
examination of the abdomen and vascular access sites will be
completed. Educational sessions will be arranged with the patient
and family to review many aspects of their medical condition. A
final session will be arranged to review the specific results of the
evaluation.
The results of the evaluation will
be discussed with the patient, family, and referring physicians.
Medical records will be made available upon request. The final
decision regarding the candidacy for intestinal transplantation is
made by a multidisciplicary patient selection committee that meets
1-2 times per month. If intestinal transplantation is recommended,
the exact types and special issues will be addressed. Otherwise,
further intestinal rehabilitation attempts may be recommended or
other non-transplant surgical options may be recommended. Sometimes,
the recommendation is to follow a patient closely to determine if
further TPN related complications can be prevented. In some
instances, patients fail the non-transplant approach and require an
abbreviated re-evaluation assessment for transplantation. A
conservative approach is taken with the patient’s best interest in
mind.
For those patients accepted for
intestinal transplantation, the process of financial clearance and
listing is undertaken. At UCLA, we accept most major government and
third party insurance carriers. Approval through the patient’s
insurance plan must be obtained prior to listing for
transplantation. Once this is obtained, the patient is listed for
the appropriate organs through the United Network for Organ Sharing
(UNOS,
www.unos.org). Each organ requires a separate listing and
status. For a patient requiring a new liver, pancreas, and
intestine, he will be listed for each organ separately with UNOS.
The listing status is based upon how diseased an organ is and organs
are distributed based upon the scoring systems in place.
Waiting times vary depending on
the UNOS score for each patient, the organs required, the size of
the patient, the blood type of the patient, and the degree of
illness of the patient. In general, most patients wait from 3 months
to 1 year for organs. This can vary from shorter to longer times
depending on the individual. Listing for transplant does not
guarantee that the appropriate organs can be found in a timely
manner. During the wait for organs, patients must have a rapid and
reliable system in place for being contacted and traveling to UCLA
to prepare for transplantation. In general, patients will have 1 to
4 hours to arrive at the medical center once contacted that an organ
has been offered to them. Families of those patients already in the
hospital at the time of organ offered will be notified immediately.
When an organ offer is obtained,
the patient will undergo a rapid medial assessment to ensure that
there are no major changes in the patient’s medical condition that
might temporarily prevent transplantation. Once completed, the
surgical team will assess the donor organ quality in an operation.
If the donor organs are not deemed suitable, the transplant will be
cancelled. If the organs are suitable, then the patient will proceed
to the operating room at UCLA to be put to sleep under anesthesia
and prepared for the transplant procedure.
Transplantation involving the
intestine requires at least 6 hours and can last as long as 12
hours. During the procedure, diseased organ or organs are often
removed. The exact operative plan will be outlined by your surgeon.
The diseased intestine (and other organs) will be replaced by new
organs. The blood flow in and out of the organ must be
re-established. Once completed and blood flow restored, the
intestine of the donor must be connected to the patient’s
gastrointestinal tract. If a patient does not have a large bowel
(colon), then a permanent ileostomy will be required. If a patient
does have functional large bowel then the transplanted small
intestine will be connected to this and a temporary ileostomy
created. The presence of an ileostomy is important for assessing the
function of the new intestine after surgery. Lastly, feeding tubes
are placed into the patient’s stomach and small intestine in the
postoperative period to provide medications and feedings.
The postoperative care will vary
from patient to patient depending on their medical condition at the
time of transplantation. Obviously the exact course for each patient
cannot be predicted nor can outcomes be guaranteed. Every effort
will be made to expedite the recovery process but patient safety is
the biggest concern. In general, patients stay in the intensive care
unit from 3 days to 4 weeks after the transplant. They may require
support on a breathing machine (ventilator) during this interval.
The length of hospitalization depends on a number of factors and can
range from 4 weeks to 3 months. While in the hospital frequent exams
and blood draws will be performed. Patients will be monitored
according to their medical condition. Biopsies of the transplanted
intestine will be obtained at regular intervals after the
transplant. A specialized formula will be used to start feeding
nutrients into the new intestine and the TPN will be weaned off as
the intestine recovers function after the transplant procedure.
Monitors, lines, and tubes will be removed as indicated.
Drugs will be given to prevent
infections and rejections. Most of the drugs are given through a
central venous catheter. Patients will be monitored closely for the
presence of infections and treated appropriately and aggressively
should these occur. The combination of drugs used to suppress the
immune system to prevent organ transplant rejection is important.
Your doctor will review these drugs with you. All drugs have
potential benefits and side-effects. They are dosed to achieve the
greatest benefit with minimal side effects. Please do not hesitate
to contact your doctor with questions regarding your medications.
The patient will not be discharged until teaching is completed and
the parents feel comfortable. Support groups are available for
transplant recipients should the patient or his family want to
attend.
