The Art of Cold Knife Conization: A Demonstration of Technique in Live Patients and a Low-Fidelity Simulation Model.

Abstract

Cervical excision via cold knife conization is recommended in circumstances such as adenocarcinoma-in-situ or predominantly endocervical high-grade dysplasia. A successful cold knife conization involves visualization, targeting of the pathology, obtaining an unfragmented specimen, and consideration of post-excision endocervical curettage. This video demonstrates cold knife conization techniques to facilitate pathologic analysis and a low-fidelity simulation model for learners. The video depicts two cold knife conizations in nulliparous patients with 1) high-grade lesion on endocervical curettage, and 2) high-grade dysplasia on ectocervical biopsy. Additionally, we demonstrate a low-fidelity simulation model that can be utilized to familiarize physicians with the conization procedure and essential hemostatic techniques. While the authors acknowledge limitations of the model to include lack of bleeding, corresponding patient cases demonstrate essential hemostatic techniques. Utilizing standard surgical instruments, cold knife conization was performed for both patients allowing for excision of an appropriately sized intact specimen. Differences in technical approach when excising the ectocervix vs. the endocervix were detailed. Endocervical curettage was performed following specimen removal, and the tissue bed was made hemostatic. Both conizations were performed without complication and negative margins were achieved. In the simulation model, easily obtainable supplies, including small cups, balloons, cling wrap, cotton balls, and hot dogs were utilized to create an imitation cervix. This can allow for demonstration and practice with suture placement, excision of an intact specimen, and hemostatic techniques. Utilizing proper technique for adequate cold knife conization specimens facilitates pathologic analysis of dysplasia, cancer, and margin status. Negative margins have a significant impact on recurrence and need for future cervical procedures, which may affect future obstetric outcomes. Low-fidelity simulation models can provide accessible avenues for technical familiarization and training in this procedure.