Endometrial biopsy (EMB) is a safe and effective method for diagnosing various endometrial abnormalities. It provides a minimally invasive assessment of the endometrium that may be used as an alternative to dilatation and curettage or hysteroscopy. Modern suction catheters have made this outpatient technique easy to learn and perform.
EMB is most commonly employed in the workup of abnormal uterine bleeding, but it can also be used for cancer screening, endometrial dating, and infertility evaluation. This technique provides part of a cost-effective diagnostic workup for abnormal uterine bleeding without reducing clinical accuracy.
Catheter-type EMBs are safe. Uterine perforations are rare unless the device is forced. Postoperative infection is rare but may be prevented with the use of prophylactic antibiotic therapy such as doxycycline (100 mg) administered twice daily for 4 days after the procedure. The patient may also be premedicated with ibuprofen (600 to 800 mg) at least 1 hour before the procedure to decrease the cramping associated with the sampling. Bacterial endocarditis prophylaxis can be considered (see Appendix I). Intraoperative and postoperative cramping is a frequent side effects of the procedure.
Some physicians prefer to apply a tenaculum and give slight countertraction toward the operator. Although a tenaculum helps stabilize the cervix, it also causes additional pain and bleeding. It may also be used to straighten a markedly anteverted or retroverted uterus and may make the procedure safer in this setting. If used, it should be applied to the anterior lip of the cervix with the teeth in a horizontal plane.
Because of the stenosis of the cervical os that develops in low-estrogen states, it can be difficult to perform an EMB in postmenopausal women. Elderly women can have a laminaria (i.e., thin piece of dried, sterile seaweed) placed in the cervix in the morning and then return in the afternoon to have the swollen (now moistened) laminaria removed immediately before the procedure. A cervical dilator may also be used when the EMB catheter can not be passed through the internal os in postmenopausal women.
Topical benzocaine solution (i.e., Hurricaine solution) may be applied to the cervix to decrease the pain from entry of the curette into the uterus. A cervical or pericervical block also may be used. For a cervical block, inject 1% to 2% lidocaine with epinephrine submucosally in the center of each cervical quadrant.
Anesthesia may be applied at any time during the procedure. Some data suggest instilling 5 mL of 2% lidocaine into the uterine cavity before endometrial biopsies significantly decreases the pain of the EMB.
Explain the procedure, and obtain informed consent. Perform a pelvic examination. Determine the size and position of the uterus. Apply povidone-iodine (Betadine) to the ectocervix and external os with a swab or cotton ball. Sound the uterus (normal depth is 6 to 9 cm).
(1) Apply povidone-iodine (Betadine) to the ectocervix and external os with a swab or cotton ball.
PITFALL: Check for masses or structural abnormalities, cervical stenosis, or signs of infection that may make the procedure more difficult or impossible.
PITFALL: When inserting the sound, apply firm, steady forward pressure to pass through the tightly closed internal os of the upper cervix. Be prepared to immediately pull back after the internal os is penetrated, or the tip of the sound can be thrust forward against the upper uterus and perforate the opposing wall. Perforations also can occur through the thin lower uterine segment. Placement of a tenaculum and straightening of the uterocervical angle can help reduce perforation after the sound passes through the internal os.
With the central piston fully inserted into the sheath (do not pull out), the endometrial sampler is inserted into the os until it reaches the fundus. Note the depth of insertion. Do not touch the end of the device that is to be inserted or allow it to touch the patient except at the os.
(2) With the central piston fully inserted into the sheath, the endometrial sampler is inserted into the os until it reaches the fundus.
PITFALL: If strong resistance is encountered, consider repeat sounding the uterus. If still unable to enter the endometrial cavity with the EMB catheter, abort the procedure. Forcing the catheter may result in uterine perforation.
PITFALL: If the catheter bends excessively, apply a small amount of torque to the catheter. This causes it to flex less.
Holding the sheath steady, pull back on the piston until it stops. This creates negative pressure inside the curette. Leave the piston fully retracted.
(3) Holding the sheath steady, pull back on the piston until it stops.
Roll or twirl the sheath laterally between the thumb and fingers while simultaneously moving the sheath tip back and forth between the fundus and internal os. Tissue should move into the sheath as the operation progresses. Complete the maneuver three or four times to obtain the sample.
(4) Roll or twist the sheath laterally between the thumb and fingers while simultaneously moving the sheath tip back and forth between the fundus and internal os.
PITFALL: Do not allow the hole in the tip to emerge from the cervix, or all of the suction will be lost.
Remove the sampling device, and cut off the distal tip (Figure 5A). Slowly push the piston completely into the sheath to expel the sample into the fixative (Figure 5B). Remove the speculum, and allow the patient to sit up and rest before dressing.
(5) Remove the sampling device, cut off the distal tip, and slowly push the piston completely into the sheath to expel the sample into the fixative.
PITFALL: Do not force the tissue out of the sampling hole without cutting the tip off because this may distort the histologic sample.
INSTRUMENT AND MATERIALS ORDERING
Catheter-type devices include the Unimar PIPELLE (Pipelle de Cornier), which can be ordered from CooperSurgical, Inc., Shelton, CT (phone: 1-800-243-2974 http://www.coopersurgical.com/), or the Wallach Endocell Endometrial Cell Sampler (20 piece box), which can be ordered from Wallach Surgical Devices, Inc., 235 Edison Road, Orange, CT 06477 (phone: 203-799-2000; fax: 203-799-2002;email:firstname.lastname@example.org; http://www.wallachsurgical.com/).
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