Cápsula endoscópica

Qué esperar al someterse a esta prueba.

La endoscopia con cápsula es un procedimiento de diagnóstico en el cual se traga una microcámara encapsulada en cápsulas para que se puedan tomar imágenes de su esófago, estómago e intestino delgado a medida que el dispositivo pasa a través de su tracto gastrointestinal (GI). Tradicionalmente, los médicos han utilizado la endoscopia , un procedimiento en el que se inserta un endoscopio en la garganta, para diagnosticar trastornos del tracto gastrointestinal superior. Pero la cápsula endoscópica ha ganado popularidad ya que es indolora, mínimamente invasiva y no requiere anestesia. Además, le permite al médico visualizar la longitud total del intestino delgado, no solo el primero de un pie o dos.

Propósito de la Prueba

La endoscopia con cápsula se usa para examinar partes del tracto GI que no se pueden ver con otros tipos de endoscopia. 

La cápsula desechable, a menudo conocida como una “cámara de píldoras”, es aproximadamente del tamaño de una tableta grande de vitaminas, lo que le permite navegar por su tracto gastrointestinal mejor que un dispositivo de alcance. Dentro de la unidad autónoma hay una cámara de video en miniatura programada para tomar entre dos y 18 imágenes por segundo, que luego se transmiten al equipo del sensor. (Una cámara de video normal toma entre 24 y 25 imágenes por segundo). También se encuentra dentro de la unidad una o varias luces LED pequeñas, un transmisor de radio y una fuente de alimentación de ocho horas.

Esta prueba se usa normalmente cuando se sospecha una enfermedad en el intestino delgado o para localizar la ubicación del sangrado, la inflamación o el daño.

Entre algunas de las razones por las que se puede usar la cápsula endoscópica:

La endoscopia con cápsula se usa generalmente para investigar la pérdida de sangre solo después de que la endoscopia o la colonoscopia no revelen la fuente de la hemorragia. Alrededor del 5 por ciento de los episodios de sangrado inexplicables provienen del intestino delgado, con mayor frecuencia de lesiones vasculares pequeñas conocidas como angioectasias .

A diferencia de la endoscopia o colonoscopia, que se puede usar para extirpar pólipos ( polipectomía ), la cápsula endoscópica solo se puede usar para diagnósticos visuales, no para tratamiento.

Exactitud

La precisión de la cápsula endoscópica puede variar según el objetivo de la investigación y el dispositivo utilizado. (Actualmente hay tres sistemas de endoscopia con cápsula aprobados por la Administración de Drogas y Alimentos de EE. UU.) Según un estudio realizado en 2015 por el Hospital Universitario de Gante en Bélgica, la endoscopia por cápsula puede diagnosticar correctamente el sangrado activo en el intestino delgado en alrededor del 58 por ciento al 93 por ciento de los casos .

Cuando se usa para diagnosticar la enfermedad de Crohn, la cápsula endoscópica se considera superior para detectar lesiones inflamatorias tempranas en comparación con todas las demás modalidades. Es 26 por ciento más preciso que una radiografía, 16 por ciento más preciso que un estudio con bario , 25 por ciento más preciso que la colonoscopia y 21 por ciento más preciso que una tomografía computarizada (TC) .

Del mismo modo, la cápsula endoscópica tiene una precisión de entre el 83 y el 89 por ciento para detectar correctamente la enfermedad celíaca , aunque aún se necesita una biopsia para un diagnóstico definitivo.

Sin embargo, debido a que la cámara simplemente se traga y se le permite abrirse paso a través de su sistema por sí sola, esta técnica de visualización es pasiva. Incluso si es más probable que el procedimiento detecte un trastorno intestinal, la imagen puede ser fugaz u oculta, lo que puede afectar las conclusiones que se pueden extraer de la prueba.

Riesgos y contraindicaciones

La endoscopia con cápsula se considera un método seguro para diagnosticar directamente el sangrado y otros trastornos GI no identificados por medios indirectos.

Existe la posibilidad, aunque leve, de que la cápsula se pueda “atascar” en el tracto digestivo (como en una bolsa intestinal causada por una enfermedad diverticular ).

También existe un riesgo de sangrado, especialmente si la cápsula pasa a través de un pasaje estrechado ( estenosis ) donde hay inflamación o daño tisular.

Si bien la obstrucción intestinal es rara en la endoscopia con cápsula, se puede usar un purgante emoliente como el polipropilenglicol para facilitar el paso de la cápsula, si es necesario. Con menos frecuencia, un procedimiento conocido como enteroscopia de doble balón (en el que dos globos se inflan y desinflan alternativamente) puede obligar a la cápsula a pasar suavemente por el lugar de la obstrucción. En casos raros, la cirugía puede ser necesaria.

La endoscopia con cápsula está contraindicada en personas con una obstrucción intestinal conocida. Se debe usar con precaución en cualquier persona que esté en riesgo de una obstrucción, incluidos aquellos con un trastorno de deglución ( disfagia ); quien esta embarazada o que tenga un marcapasos u otro dispositivo cardíaco implantado.

Antes de la prueba

La endoscopia con cápsula no requiere anestesia. Dicho esto, requiere muchas de las mismas preparaciones utilizadas para un procedimiento endoscópico tradicional.

Sincronización

El procedimiento de endoscopia con cápsula requiere un ayuno durante la noche y, como tal, siempre se programa a primera hora de la mañana. Una vez que se aplica el equipo del sensor y se traga la cámara de la píldora, las imágenes continuarán automáticamente a medida que avanza su día. La prueba se completa cuando evacua la pastilla-cam en las heces o después de ocho horas, lo que ocurra primero.

Ubicación

Capsule endoscopy can be performed at a gastroenterologist office, a gastroenterology procedure unit of a hospital, or an independent endoscopy center available in some cities.

What to Wear

Eight adhesive sensors will need to be placed on parts of your abdomen. To reduce sweat and make application easier, wear a light, untucked cotton T-shirt. As the sensors will transmit to a sensor belt or data recorder that you must wear around your waist (if not over your shoulder with a holster), choose a shirt that is long enough to reach at least hip level and will not ride up. Your outfit should be one you won’t need to change out of for at least eight hours, as the equipment must remain in place until the test is over.

Food and Drink

You will need to stop eating and drinking at least 12 hours before the procedure. This helps improve the image quality as the pill-cam makes its way through the digestive tract.

Generally speaking, you will need to stop eating solid food at around noon the day before the test. Until 10:00 p.m., you can consume liquids, such as water, coffee, tea broth, clear broth, clear soda, and gelatin. Avoid milk or any liquid or gelatin that is red or purple (this may register on camera as blood).

Some doctors may instruct you to take 10 fluid ounces of magnesium citrate at 7:00 p.m. The over-the-counter product can help gently clear stools from the body. Be sure to get the light-colored (lemon-lime) formulation, rather the red (cherry-flavored) one.

From 10:00 p.m. until the time you swallow the pill-cam the next day, you will need to stop all fluids, including water. Other food restrictions should continue for the duration of the test.

Medications

Some medications will also need to be stopped before the capsule endoscopy procedure. Chief among these are iron supplements or any multivitamins containing iron. Iron can not only stain the walls of the intestines; it can make it far more difficult to pass the capsule.

As such, you will need to stop taking iron-containing supplements three to four days before the test. You may also be advised to avoid strenuous exercise a day in advance as it may slow peristalsis, the rhythmic contraction of gastrointestinal tissue.

Pepto-Bismol (bismuth subsalicylate) should also be stopped three or four days in advance because it can also affect peristalsis and leave black-colored deposits.

While blood thinners and aspirin are typically avoided prior to traditional endoscopy (due to the risk of bleeding), they pose no such risk for capsule endoscopy.

Finally, if you take chronic medications, you may need to delay doses until two hours after the pill-cam is swallowed. Speak with your doctor to make the appropriate adjustments so that you don’t entirely miss your daily dose.

What to Bring

Be sure to bring your ID and health insurance card to your appointment. If you have to delay a medication dose and are not planning to return home after the test is started, be sure to bring the dose with you.

Cost and Health Insurance

Depending on where you live, capsule endoscopy can cost anywhere from $1,000 to $2,000. That still represents a savings of $750 to $1,000 compared to traditional endoscopy.

Insurance pre-authorization is required for the test. Ultimately, the decision to authorize is based on the prescribed treatment guidelines and the associated ICD-10 diagnostic code. In some cases, capsule endoscopy may only be approved after traditional endoscopy has been performed.

Call your health insurance representative to understand what the guidelines dictate. If the procedure is denied, your doctor may be able to provide additional motivation as to why the procedure to essential. Unfortunately, cost savings is not usually a motivating factor.

If you are uninsured or cannot afford the copay or coinsurance costs, shop around for the best price. Independent endoscopy centers may offer nominal savings. Ask if there are monthly payment options or a discount if the payment is made up front.

Other Considerations

If you are especially hairy, you may be asked to shave parts of your chest and abdomen in order to affix the sensors. Doing so in advance will save you time at the doctor’s office.

Though the equipment can be bulky and cumbersome, some people choose to work or continue their normal daily routine during the test. Others stay home. While the belt and data recorder are portable, they are not invisible.

During the Test

Capsule endoscopy is a relatively straightforward procedure. The preparation takes place in the doctor’s office or a procedure center. The remainder of the test continues as you go about your day.

Pre-Test

After signing in with your ID and health insurance information, you will be led to the procedure room by a doctor or endoscopic technician. You will remove your shirt and the sensors – each containing an antenna and long wires – will be applied. The sensor belt will be strapped around your waist over your shirt; if a separate recording device is being used, it will be slung over your shoulder with a strap. The wires will then be attached to whichever unit was provided. You can then replace your shirt.

Once all the equipment is in place and checked out, you will swallow the pill-cam with a little water. (Its slippery outer coating helps it go down easy.) You shouldn’t be able to feel the pill-cam from then on.

All told, the preparations will take around 15 minutes, barring delays. You are then free to leave office, drive, and even return to work if appropriate. You must avoid strenuous physical activity and follow specific dietary guidelines throughout the day.

Throughout the Test

The actual imaging starts the moment you swallow the pill cam. The camera will “telecast” the images it takes to the sensors, and the signals will be delivered to the sensor belt or recording device (either wirelessly or via cables).

While instructions can vary, you will generally be able to resume any medications two hours into the test. You will also be allowed to consume clear liquids, including broth or a light-colored sports drink. After four hours, you will usually be permitted to have a light lunch or at least a snack. After that, your doctor will ask you to continue a liquid diet until you either see the pill-cam in the toilet after a bowel movement or reach the eight-hour mark. When that happens, the test is over.

Post-Test

The pill-cam is disposable and can be flushed down the toilet. You can then remove the patches, belt, and data recorder.

You can return to your normal routine and diet unless your doctor tells you otherwise. The morning after your test is done, you will need to return the equipment to the doctor’s office so that the images can be downloaded and reviewed by a gastroenterologist. The test results are usually available within a week.

After the Test

It may take some people hours or days to evacuate the pill-cam; most people pass it in 24 to 72 hours. If you unable to spot the pill-cam in your stools after two weeks, call your doctor. An X-ray may be needed to see if the device is stuck somewhere in your digestive tract.

Some people may experience constipation after the procedure, which usually resolves within a couple of days. To help normalize your bowel movements, drink plenty of fluids and increase your intake of insoluble fiber. If needed, speak with your doctor about an over-the-counter laxative or stool softener if constipation persists.

While bowel obstruction or injury is rare, call your doctor if you experience any abdominal pain, bleeding, fever, bloating, or are unable to pass gas.

Interpreting the Results

A capsule endoscopy report is more or less the same as a traditional endoscopic report. The report will contain a list of normal and abnormal findings, along with preliminary interpretations.

It will also include details about bowel preparation, the quality of bowel preparation, the extent and completeness of the exam, relevant findings, and so-called “pertinent negatives” (expected findings that the patient denies having).

While some findings can be readily observed, such as bleeding or strictures, others may be ambiguous.

On its own, capsule endoscopy is not inherently diagnostic, but it can often be used in tandem with other evaluations to reach a definitive diagnosis. If a conclusive diagnosis is not achieved, additional evaluation or review of your results by other specialists may be needed.

Follow-Up

Follow-up may be needed if there are any abnormal findings. While some, like bleeding or an obstruction, can be used to direct treatment, others may require further investigation given the limitation of what a visual image can confirm.

One such example is the detection of polyps during the procedure. While certain characteristics of a polyp may be suggestive of cancer (including a larger size and increased vascularity), an endoscopic procedure called esophagogastroduodenoscopy (EGD) may be needed to remove and definitively diagnose the growth in the lab. On the other hand, growths that are consistent with cancer (including bleeding, growth clusters, and an irregular, non-capsulated structure) may require laparoscopic or open surgery.

Similarly, while some disorders like celiac disease may be treated presumptively based on the visual findings, many doctors will insist on obtaining a tissue sample so that the disease can be typed and treated appropriately.

In some cases, the test may need to be repeated to obtain better images, particularly if symptoms persist despite a negative result. A retrospective study conducted in 2010, which evaluated 82 people who had undergone more than one capsule endoscopic procedure, concluded that a repeat test yielded a change in treatment in 39 percent of cases. Moreover, nearly half of the people who had an incomplete first test (10 out of 22) had an abnormal finding in the second.

Bone Marrow Transplantation at | 832-533-3765 | [email protected] | Website

I am Dr. Christopher Loynes and I specialize in Bone Marrow Transplantation, Hematologic Neoplasms, and Leukemia. I graduated from the American University of Beirut, Beirut. I work at New York Bone Marrow Transplantation
Hospital and Hematologic Neoplasms. I am also the Faculty of Medicine at the American University of New York.