Download enterrA® therApy SyStem

enterrA
therapy System
®
Gastric Electrical Stimulation
Lynn
Enterra Therapy patient
ENTERRA® THERAPY FOR
GASTROPARESIS
Enterra® Therapy is an innovative approach to
treating patients with chronic, intractable (drugrefractory) nausea and vomiting secondary to
gastroparesis of idiopathic or diabetic origin. The
therapy uses mild electrical pulses to stimulate
the nerves of the antrum. This stimulation may
reduce the symptoms of nausea and the number
of vomiting episodes related to gastroparesis.1
Introduced by Medtronic, Inc., the world leader in
implantable medical technologies, Enterra Therapy
can be turned off or removed if there is no longer
a benefit.
GASTROPARESIS AND ITS SYMPTOMS
Gastroparesis is a neuromuscular stomach disorder
in which food empties from the stomach more
slowly than normal. In most people, undigested
food moves from the stomach into the duodenum
and small intestine within two to four hours after
eating. In contrast, patients who have gastroparesis
will retain a significant amount of food in the
stomach hours after eating.
Patients with gastroparesis experience a variety
of upper gastrointestinal symptoms that prevent
them from eating normally and that may lead to
dehydration, weight loss, and eventually lifethreatening electrolyte imbalances and malnutrition.
Moreover, delayed stomach emptying interferes
with oral drug absorption and, in patients with
diabetes mellitus, prevents effective control of
blood glucose levels.
Being aware of key symptoms can help you
recognize the disease for timely referral of
patients to gastric health specialists.
Chronic nausea and frequent vomiting are the
most debilitating symptoms of gastroparesis,
differentiated from other disorders by key warning
signs, such as:
• Nausea and/or vomiting occurring several
times a day and episodes occurring for longer
than 12 months
• Repeated hospitalizations and supplemental
nutrition needed due to nausea and/or vomiting
• Inadequate relief of symptoms from
medications for nausea and/or vomiting
• Diminished quality of life due to chronic nausea
and/or vomiting
• Weight loss or excessive weight gain over the
past year due to improper nutrition resulting
from chronic nausea and/or vomiting
In addition to nausea and vomiting, symptoms
of gastroparesis may include: 1
• Abdominal bloating and/or pain
• Early satiety after only a few bites of food
• Heartburn or GERD
• Changes in blood sugar levels
• Lack of appetite
ETIOLOGY OF GASTROPARESIS
Causes of
Gastroparesis
In a survey of 146 patients with documented
gastroparesis, idiopathic and diabetic origin were
the two most common etiologies.2
Idiopathic gastroparesis accounted for
35.6% of cases.
Diabetes, either Type 1 or Type 2 accounted
for 29.0% of gastroparesis cases. High blood
Diabetes
29.0%
glucose levels and their metabolic effects can
damage the vagus nerve over time and interfere
with normal function. In turn, the inconsistent
stomach emptying and poor absorption associated
with gastroparesis make blood sugar levels harder
to control.
Other
35.4%
The survey noted that several other causes
accounted for the remaining (35.4%) cases of
gastroparesis. Enterra Therapy is not indicated
for use in patients with gastroparesis resulting from
these other causes.
TREATMENT OPTIONS FOR
GASTROPARESIS
There is no cure for gastroparesis but there are
treatment options that can control the symptoms
of chronic vomiting and nausea. Often, multiple
therapies are used in combination.3 An overview
of care for gastroparesis includes:
Antiemetic
drugs
Enterra® Therapy
Diet modification
G astroparesis T reatment O ptions
Psychological
support
Enteral nutrition
Prokinetic drugs
Total parenteral
nutrition (TPN)
Gastrectomy
Idiopathic
35.6%
ENTERRA THERAPY SYSTEM
The Implanted Enterra Therapy System
The Enterra Therapy System for gastroparesis
received humanitarian device exemption (HDE)
approval from the FDA in March 2000. The HDE
authorizes Medtronic to market the Enterra
Therapy System for the treatment of chronic
intractable (drug-refractory) nausea and vomiting
secondary to gastroparesis of diabetic or idiopathic
etiology. The effectiveness of this device for
this use has not been demonstrated. The Enterra
Therapy System may only be used in medical
centers in which an institutional review board (IRB)
has approved use of the device.
Enterra Therapy may control symptoms but is
not a cure for gastroparesis. Often, a combination
of therapies is needed to adequately control
symptoms. Rate of improvement varies from
person to person.
Enterra Therapy System components consist of:
• A small battery-powered neurostimulator
(about the size of a pocket watch), implanted
beneath the skin in the lower abdominal region
• Two intramuscular leads implanted in the muscle wall
of the stomach and connected to the neurostimulator
• A handheld, external programmer, used
by the physician to noninvasively adjust
therapy specifically for each patient, assess
neurostimulator battery status, and perform
troubleshooting
The surgical procedure for Enterra Therapy is
performed under general anesthesia and takes 1 to 2
hours. Using laparotomy or laparoscopy, the implanting
physician inserts the stimulating electrode of each
lead into the antrum muscle. The lead bodies are
routed under the skin to the neurostimulator where
the connector ends of the leads are attached. The
neurostimulator is then placed in a small pocket
through an incision in the abdomen.
Patient Selection Criteria
for Enterra Therapy
Many symptoms of gastroparesis mimic those
of other disorders or are the result of side effects
from certain medications, making it difficult to
reach a definitive diagnosis.
Patients suspected to have gastroparesis should
be evaluated for Enterra Therapy based on the
following:
a Documented gastroparesis of diabetic or
idiopathic origin based on nuclear medicine
emptying study
b Chronic nausea and/or vomiting
c Refractory or intolerant to prokinetics/
antiemetics
d Must be viable surgical candidate
e Symptoms must be of physiological origin
f Patients are recommended to undergo
detoxification from narcotics prior to implant
wavess
Median Weekly Vomiting (episodes/week)6
Lynn
Enterra Therapy Patient
Safety and Probable BENEFIT
OF ENTERRA THERAPY
In a multicenter clinical study (WAVESS— Worldwide
Anti-Vomiting Electrical Stimulation Study),
a majority of patients experienced improvements
in weekly vomiting episodes after receiving an
Enterra Therapy implant compared to the number
of vomiting episodes before Enterra Therapy.4
Thirty-three (33) patients with chronic
gastroparesis were enrolled in the study (17 of
diabetic origin and 16 of idiopathic origin).
Symptoms were compared between baseline
and 6 and 12 months.
At both follow-ups and for both patient groups,
the median weekly vomiting episodes
were significantly reduced:
• At 6 months after implant, the median
vomiting frequency declined 80% for the
diabetic group and 88% for the idiopathic group
(n = 27).
• At 12 months after implant, the median
vomiting frequency declined 63% for the
diabetic group and 83% for the idiopathic group
(n = 24).
In addition to risks related to a medical
procedure, adverse events related to the
system include but are not limited to infection,
stomach wall penetration, migration/erosion of
the neurostimulator, programming difficulty,
undesirable change in stimulation, hemorrhage,
hematoma, migration of the lead, abdominal
pain, seroma, concomitant muscle stimulation,
allergenic or immune system response to
implanted materials, loss of therapeutic effect,
and gastrointestinal complications including
small bowel obstruction.
ADDITIONAL WAVESS RESULTS:
Support Materials
Evaluation of secondary endpoints
showed many patients experienced
improvement in:
A number of patient screening and educational
tools, as well as a listing of current U.S. Centers
specializing in Enterra Therapy, are available
from Medtronic. For more information, please
call 1-800-510-6735 or visit medtronic.com.
• Quality of life (73%)
• Ability to tolerate solid meals (73%)
Also, there was a trend in improvement for gastric retention, subjective
symptoms, and hypoglycemic attacks.
References
1. Abell T, McCallum R, Hocking M, et al. Gastric electrical
stimulation for medically refractory gastroparesis.
Gastroenterology. 2003;125(2):421-428
2. Soykan I, Sivri B, Sarosiek I, Kiernan B, McCallum RW.
Demography, clinical characteristics, psychological and
abuse profiles, treatment, and long-term follow-up of
patients with gastroparesis. Dig Dis Sci. 1998;43(11):
2398-2404.
3. Abell TL, Bernstein RK, Cutts T, et al. Treatment of
gastroparesis: a multidisciplinary clinical review.
Neurogastroenterol Motil. 2006;18(4):263-283.
4. Medtronic, Inc. Enterra Clinical Study Results:
HDEH990014. Minneapolis, MN: Medtronic Inc., 2000.
Enterra® Therapy for Gastroparesis: Product technical manual must be reviewed
prior to use for detailed disclosure.
Indications: The Medtronic Enterra Therapy System for gastric electrical
stimulation (GES) is indicated for use in the treatment of chronic, intractable
(drug refractory) nausea and vomiting secondary to gastroparesis of diabetic or
idiopathic etiology.
Contraindications: The Enterra Therapy System is contraindicated in patients
whom the physician determines are not candidates for surgical procedures and /
or anesthesia due to physical or mental health conditions.
Do not use shortwave diathermy, microwave diathermy or therapeutic ultrasound
diathermy (all now referred to as diathermy) on patients implanted with a
neurostimulation system. Energy from diathermy can be transferred through the
implanted system and can cause tissue damage at the location of the implanted
electrodes, resulting in severe injury or death.
Diathermy is further prohibited because it can also damage the neurostimulation
system components resulting in loss of therapy, requiring additional surgery
for system explantation and replacement. Injury or damage can occur during
diathermy treatment whether the neurostimulation system is turned “on” or “off.”
Advise your patients to inform all their health care professionals that they should
not be exposed to diathermy treatment.
Warnings/Precautions/Adverse Events: This system has not been evaluated for
pregnancy, pediatric use, or patients under the age of 18, or over the age of 70.
Strong sources of electromagnetic interference (EMI) can result in serious injury,
system damage, or operational changes to the system. Strong sources of EMI
include MRI, electrocautery, radiofrequency (RF)/microwave ablation, external
defibrillators, and theft detectors. Patients on anticoagulation therapy may be
at a greater risk for post-operative complications. The system may be affected
by or adversely affect other implantable devices such as cardiac pacemakers
and cardioverters/ defibrillators. The use of non-Medtronic components with
this system may result in damage. Adverse events related to the system include
infection, stomach wall penetration, migration/erosion of the neurostimulator,
programming difficulty, undesirable change in stimulation, hemorrhage, hematoma,
migration of the lead, abdominal pain, seroma, concomitant muscle stimulation,
allergenic or immune system response to implanted materials, loss of therapeutic
effect, and gastrointestinal complications including small bowel obstruction.
Humanitarian Device: Authorized by Federal law for use in the treatment of chronic
intractable (drug refractory) nausea and vomiting secondary to gastroparesis of
diabetic or idiopathic etiology. The effectiveness of this device for this use has not
been demonstrated.
Caution: Federal law (USA) restricts this device to sale by or on the order of a
physician.
World Headquarters
Medtronic, Inc
710 Medtronic Parkway
Minneapolis, MN 55432-5604
USA
Internet: www.medtronic.com
Tel. 763-505-5000
Fax 763-505-1000
Toll-free 800-328-0810
UC200804978 EN NI8603
© Medtronic, Inc. 2008
All Rights Reserved
Printed in USA