Conization of the Cervix

Definition

• Pfenninger and Fowler's Procedures for Primary Care, p. 935-937
• Berek & Novak's Gynecology, p. 865

Types of Conization

Indications

Diagnostic Indications

• Inadequate colposcopic evaluation (entire lesion or TZ/SCJ not visualized)
• Lesion extends into the endocervical canal beyond colposcopic view
• Positive endocervical curettage (ECC) - dysplasia or cancer found
• Significant discrepancy between cytology, colposcopic impression, and biopsy (e.g., Pap smear at least two grades worse than biopsy)
• Inability to exclude invasive cancer on colposcopy
• CIN 3 or AGC-AIS (adenocarcinoma in situ) confirmed on biopsy

Therapeutic Indications

• Cytology or biopsy suggests microinvasive carcinoma (to rule out frank invasion)
• High-grade dysplasia (CIN 2-3) >2 cm or involving more than 2 quadrants
• Lesion too large for cryotherapy or cryo is contraindicated
• Markedly irregular cervical surface crevices that cryotherapy cannot reach
• Glandular involvement on biopsy
• Lesion extends >5 mm into the os
• Patient unlikely to comply with follow-up after less definitive treatment

Contraindications

• Known frank invasive cervical/endocervical carcinoma (microinvasive cancer is NOT an absolute contraindication - conization is actually required to rule out frank invasion)
• Contraindications to general or regional anesthesia
• Unstable medical conditions

• Unstable bleeding disorders / coagulopathy
• Active cervicitis / heavy menses (increased bleeding risk)
• Pregnancy (see note below)
• Diethylstilbestrol (DES) exposure in utero
• <12 weeks postpartum
• Preexisting short cervix (consider referral)

Pregnancy note: Not an absolute contraindication, but only a well-trained physician capable of managing complications should operate. Fetal loss rate is ~10% (from membrane rupture, preterm labor, hemorrhage), and postoperative hemorrhage rate is ~30%.

Procedure (Cold-Knife Conization)

1. Anesthesia - general, regional, or local (intrastromal) anesthesia; drain bladder
2. Lesion demarcation - apply full-strength Lugol's solution (iodine-negative areas = abnormal) or acetic acid + green filter colposcopy to outline the transformation zone
3. Hemostasis - circumferentially infiltrate cervical stroma with vasopressin 20 U in 20 mL normal saline; figure-of-eight retention sutures at 3 and 9 o'clock to ligate descending branches of the uterine artery (CKC)
4. Sound the uterus - assess canal position and size
5. Incision - begin at 6 o'clock (so blood runs away from the incision line), angle the blade centrally toward the endocervical canal; excise outside the Lugol's-negative/acetowhite area
6. Specimen orientation - place a marking suture at 12 o'clock; grasp with Allis clamps to maintain orientation
7. Endocervical curettage (ECC) - performed above the cone biopsy
8. Hemostasis - running locked suture, Sturmdorf stitch, or hemostatic agents (Surgicel, Gelfoam)

• Premenopausal: broad base, wide angle at top (ectocervical lesions predominate)
• Postmenopausal: long and narrow, acute apex (SCJ has receded into the canal; endocervical lesions more likely)

Pathologic Assessment and Margins

• Positive margins significantly increase recurrence risk after conization
• Endocervical gland involvement is predictive of recurrence: 23.6% with gland involvement vs. 11.3% without
• If ectocervical margins show only dysplasia: follow closely; repeat cone not routinely indicated (lesion often resolves during healing)
• If ECC above the excisional site is positive with high-grade lesion: repeat conization should be considered
• Adenocarcinoma in situ (AIS): high rate of coexisting squamous lesions (~58% in one series); margins are less reliable and hysterectomy is often recommended after conization

Outcomes: CKC vs. LEEP vs. Laser

Complications

Post-Procedure Management

• Follow-up at 4-6 weeks
• Avoid intercourse, douching, and tampons until healing confirmed
• Report fever, excessive bleeding, or purulent discharge
• First follow-up Pap smear at 3-4 months if margins are clear
• Pfenninger and Fowler's Procedures for Primary Care, p. 937
• Berek & Novak's Gynecology, p. 865
• Sabiston Textbook of Surgery, p. 2793

Recent Evidence (2024-2026)