Loop Electrosurgical Excision Procedure (LEEP)
Cervical conization (also known as cone biopsy) refers to the excision of a cone-shaped portion of the cervix surrounding the endocervical canal and including the entire transformation zone.
Introduction
Cervical conization (also known as cone biopsy) refers to the excision of a cone-shaped portion of the cervix surrounding the endocervical canal and including the entire transformation zone. Excisional treatment can be performed using a scalpel, laser, or electrosurgery (ie, loop electrosurgical excision procedure [LEEP], also called large loop excision of the transformation zone [LLETZ]). There is no evidence that one technique is significantly better than another.
Since squamous lesions typically arise at the transformation zone, the procedure usually enables the pathologist to study an intraepithelial or superficially invasive lesion in its entirety. However, conization does not always remove the entire transformation zone or lesion. Excision is less likely to be complete in certain situations, such as pregnancy, or when the transformation zone is large or high in the endocervical canal, or when the lesion extends onto the vaginal fornices or very deep into the cervical stroma.
Ablative procedures, which are usually done with cryosurgery or with the laser, are an alternative to conization. However, no pathologic specimen is obtained since the cervical tissue is destroyed. These procedures are purely therapeutic and not of diagnostic value. They are appropriate for selected patients with previously well characterized lesions histologically and colposcopically, in whom invasive cancer has been excluded.
Operative Technique
The goal of cone biopsy is to remove the entire transformation zone. Too small of an excision can result in inadequate removal of the lesion, while an excision that is too large can lead to immediate and delayed complications. The size and shape of the cone biopsy should be tailored to the individual situation and based upon careful preoperative colposcopy and good surgical judgment. Colposcopy in the operating room just before cone biopsy is not always practical, but may be helpful in many situations. Extending colposcopy to include evaluation of the upper vagina is worthwhile, especially in the presence of large, high-grade ectocervical lesions.
If the transformation zone and lesion are in the endocervical canal and the exocervix appears normal, the cone biopsy may be made narrower to preserve the normal ectocervical tissue, but should extend well upward along the endocervical canal. By comparison, if the lesion and transformation zone are largely confined to the ectocervix and the endocervical canal appears to be free of disease, then the cone is taken wide enough to clear the transformation zone with minimal resection of the endocervical canal.
The use of vasopressin and postprocedure packing decreases perioperative blood loss and menstrual symptoms. A systematic review of three randomized trials reported the following major results:
- Cervical injection of vasopressin before biopsy reduced perioperative blood loss in cold knife and laser conization.
- Packing of the biopsy site with a rolled gauze dipped in ferric subsulfate solution (Monsel’s solution) resulted in a twofold reduction in the incidence of secondary hemorrhage compared with lateral cervical sutures after cold knife conization.
- Packing of the biopsy site with a rolled gauze dipped in ferric subsulfate resulted in a decreased risk of amenorrhea or dysmenorrhea compared with lateral cervical sutures at four months after cold knife conization.
Cold knife Conization
Cold knife conization is performed with a scalpel, almost always under general or regional anesthesia. The patient is placed in the dorsal lithotomy position. Many surgeons drain the bladder to protect against bladder injury. We, however, do not drain the bladder since we do not find this necessary for bladder protection, and catheterization may increase the risk of a postoperative urinary tract infection. A digital examination is not done and the vagina is gently prepared to avoid trauma to the cervix leading to possible difficulty with histologic interpretation of the specimen. A weighted speculum of appropriate length and narrow Deaver retractors are placed to allow visualization the cervix.
Colposcopic examination may be performed, and some surgeons use Lugol’s iodine or 3 to 5 percent acetic acid solution to help demarcate the outer limits of the transformation zone. These procedures help the surgeon decide as to the size and configuration of the cone. Deeper cones (2 cm or more) are necessary in postmenopausal women undergoing conization because the squamocolumnar junction tends to move cephalad into the endocervical canal.
The anterior lip of the cervix is grasped with a single tooth tenaculum well outside the transformation zone, so as not to interfere with the excision. If room allows, a tenaculum placed on the posterior cervical lip is also helpful. In women with an abnormally shaped cervix (eg, “fish mouth” cervix), the specimen may need to be removed in pieces. The tenaculum is moved from one location to another to facilitate this. Although many surgeons recommend the placement of absorbable sutures at the three and nine o’clock positions just below the cervicovaginal junction (sutures placed too deeply may be cut during excision) this has not been shown to be the optimal technique.
A vasoconstrictor solution may be injected into the cervix now, if there are no medical contraindications (eg, hypertension). Use of the solution reduces intraoperative blood loss and thereby improves operative exposure, allowing the surgeon to do a more controlled and accurate cone biopsy. We use 20 to 30 mL of vasopressin (0.5 U/mL) or 1:200,000 epinephrine solution injected with a 1.5-inch, 21-gauge needle circumferentially deep into the dense cervical stroma, just lateral to the planned line of resection.
A long-handled scalpel with a #11 blade is used to make a circumferential incision just lateral to the outer limit of the transformation zone. Starting posteriorly, the scalpel blade is inserted to the desired depth and direction (in general, slightly toward the endocervical canal). Using a very slight sawing motion (more like pushing) to keep the scalpel at the same depth and angle, the desired circular incision is completed. A uterine sound may help guide the path of the incision when a significant portion of the endocervical canal must be removed; care should be taken not to traumatize the endocervical canal.
An Allis clamp is used to gently grasp and manipulate the partially released specimen, being careful to avoid the mucosal surfaces. Mayo scissors are used to complete and deepen the incision as necessary. The specimen is then removed by cutting across the remaining base with Jorghenson scissors. The residual endocervical canal is then curetted.
Routine dilation and endometrial curettage is unnecessary, except in women in the menopausal transition and postmenopausal women, those with abnormal glandular cytology, and women who otherwise have factors placing them at risk of endometrial pathology, such as abnormal bleeding. In those patients in whom dilation and curettage is indicated, the conization is done first to preserve cervical architecture.
Optimal management of the cone bed is not well established. A variety of suture techniques have been described, such as a modification of Sturmdorf type sutures. We use these sutures when there is significant bleeding from the cone bed or when a large cone biopsy has been taken. There is some concern, however, that sutures placed into the cone bed may interfere with healing. Another hemostatic measure is to firmly place in the cervix a tampon or rolled gauze soaked in ferric subsulfate solution; the pack can removed by the patient pulling the string in 12 to 24 hours.
Alternatively, an open cone bed technique can be performed. This procedure is approached by obtaining spot hemostasis with electrocautery. A long, narrow piece of oxidized cellulose (eg, Surgicel) is then carefully packed into the cone bed and secured by tying the two lateral cervical sutures across the midline over the surgical pack. The patient must be warned that she will pass this pack within one to two weeks. Ideally, the procedure is timed so that menstrual flow does not occur while the pack is in place. The vagina is generally not packed and the patient is sent home the same day or the next morning.
It is useful for the surgeon to measure the width and vertical depth of the cone specimen in the operating room and describe these measurements in the operative note. Measurements taken later, such as in the pathology laboratory, may be inaccurate due to shrinkage of the specimen.
If the cervix has a large defect, care must be taken in that area to not enter the peritoneal cavity with the knife blade. Should this occur, laparoscopy to examine the pelvis may be indicated. Similarly, if the anterior cervix is absent and the blade is felt to have gone too deep, cystoscopy may be appropriate to examine the bladder.
Request Your Consultation Now
Request a consultation at BellaDonna MD. Ready to get started? Call us today or fill out the form below.
BellaDona Medical P.C © 2022. All Rights Reserved. Privacy Policy