title: Comparison of the depth of tissue necrosis between double-freeze and single-freeze nitrous oxide-based cryotherapy.
abstract: BACKGROUND
  Cryotherapy is one the methods of treating cervical premalignant lesions. It is particularly suitable for low-resource countries because of it is relative cheaper, has low cost of maintenance, ease of use and that does not require electricity which is in short supply in many rural areas of developing countries where the incidence and mortality from cervical cancer is very high. In this study we compared single and double freezing on the cervices of women admitted for hysterectomy for benign conditions using Nitrous-based cryotherapy.
  
  
  METHODS
  Patients admitted for elective hysterectomy for benign gynaecological conditions were randomized into two arms. The first group had single freeze cryotherapy while the second arm received double freeze cryotherapy. The cervices were examined 24 hours later to determine the depth of tissue necrosis.
  
  
  RESULTS
  In this comparative study, the depth of tissue necrosis was deeper with double freeze compared with single freeze. Also in both arms, the depth of necrosis was deeper on anterior lips than on posterior lips of the cervix.
  
  
  CONCLUSIONS
  Double freeze technique achieve more depth of tissue necrosis than single-freeze on both anterior and posterior lips of the cervix.
authors.affiliation: Department of Obstetrics and Gynaecology, State Specialist Hospital, Akure, Ondo State, Nigeria.
authors.forename: Akinfolarin Clement
authors.initials: AC
authors.lastname: Adepiti
authors.affiliation: Department of Obstetrics and Gynaecology, Gynae-Oncology Unit, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria.
authors.forename: Olusegun Kayode
authors.initials: OK
authors.lastname: Ajenifuja
authors.affiliation: Department of Morbid Anatomy and Histopathology, Federal Medical Centre, Lokoja, Benue State, Nigeria.
authors.forename: Oluwaseyi Olatunji
authors.initials: OO
authors.lastname: Fadahunsi
authors.affiliation: Department of Histopathology, State Specialist Hospital, Akure, Ondo State, Nigeria.
authors.forename: Stephen Adebayo
authors.initials: SA
authors.lastname: Osasan
authors.affiliation: Department of Histopathology, State Specialist Hospital, Akure, Ondo State, Nigeria.
authors.forename: Olumuyiwa Eyitayo
authors.initials: OE
authors.lastname: Pelemo
authors.affiliation: Department of Obstetrics and Gynaecology, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Osun State, Nigeria.
authors.forename: Morebishe Olabisi
authors.initials: MO
authors.lastname: Loto
keywords: Carbon dioxide; cervical premalignant lesions; cryotherapy; nitrous oxide