Impact of conization type on the resected cone volume: results of a retrospective multi-center study.

Purpose: The extent of conization seems to influence the risk of preterm birth. The aim of this study was to compare the cone volume after surgical resection with large loop excision of the transformation zone (LLETZ) and cold knife conization (CKC).
Methods: The present retrospective multi-center study comprises 804 consecutive women, who underwent LLETZ (n = 412) or CKC (n = 392) between 2004 and 2009. Univariate and multivariable analyses were performed to compare cone volumes removed by LLETZ and CKC and identify independent risk factors for large cone volume.
Results: The median resected cone volume after LLETZ was significantly smaller [1.6 cm(3) (0.8-2.9)] than after CKC [2.1 cm(3) (1.4-3.5)] (<0.0001). Complete resection rates were comparable in both groups. Conization method, cone depth, and institution type were independent risk factors for removal of a large cone volume.
Conclusion: CKC removes larger cone volumes than LLETZ without the advantage of higher complete resection rates.