Loop Electrosurgical Excision Procedure (LEEP): Technique and Specimen Collection
LEEP uses a thin wire loop electrode with electrical current to excise abnormal cervical tissue in a cone-shaped specimen that can be examined histologically, performed as an outpatient procedure under local anesthesia. 1
Procedural Technique
The procedure involves the following key steps:
A thin stainless steel or tungsten wire loop attached to a low-current, high-frequency electrical generator is used to excise either specific lesions or the entire transformation zone 2
The loop electrode allows deep excision of the transformation zone, removing a cone-shaped piece of tissue that maintains its structural integrity for pathological examination 3
Local anesthesia is typically sufficient, with patients experiencing minimal to no noticeable pain during the procedure 3
The entire procedure can be completed at the first visit without requiring general anesthesia or hospital admission 3, 2
Traction sutures of the cervix may be placed to manipulate the cervix outward and away from nearby protruding tissues, particularly in patients with cystocele or rectocele, reducing the risk of inadvertent lacerations 4
Specimen Collection and Handling
The tissue collection process is designed to provide optimal diagnostic material:
The excised tissue is removed as a cone-shaped, preferably non-fragmented specimen that allows complete pathologic assessment 5
The goal is to achieve 3-mm negative margins when performing the excision, particularly important for fertility-sparing approaches 5
Endocervical curettage (ECC) should be added as clinically indicated to ensure complete evaluation of the endocervical canal 5
The specimen must be properly oriented to allow pathologists to assess margin status accurately 5
Critical Considerations for Specimen Quality
Cold knife conization (CKC) is the preferred method when specimen quality is paramount, but LEEP is acceptable provided adequate margins and proper orientation are obtained 5:
LEEP can create thermal artifacts at the tissue margins that may compromise pathologic evaluation, particularly problematic when evaluating for microinvasive cervical cancer 5, 1
When microinvasive disease is suspected based on biopsy findings, CKC provides superior specimen quality without thermal damage 1
Complete excision rates with LEEP are approximately 84%, with margins not securely cleared in 13.5% of cases and incomplete excision in 2.2% 6
Common Pitfalls to Avoid
Fragmented specimens compromise pathologic interpretation - use appropriate loop size and technique to obtain a single, intact cone specimen 5
Inadequate depth of excision - ensure the entire transformation zone is removed rather than selectively targeting only the visible lesion 5
Failure to perform endocervical sampling when indicated can miss residual disease in the endocervical canal 5
Thermal artifact at margins - when cancer is suspected, consider CKC instead to avoid compromising the pathologist's ability to assess invasion 5, 1