title: Enzymatic digestion improves testicular sperm retrieval in non-obstructive azoospermic patients.
abstract: BACKGROUND
  In patients with non-obstructive azoospermia (NOA), vital spermatozoa from the tissue is obtained from testes by enzymatic treatment besides the mechanical treatment.
  
  
  OBJECTIVE
  To increase the sperm recovery success of testicular sperm extraction (TESE), with enzymatic digestion if no sperm is obtained from testis tissue by mechanical method.
  
  
  METHODS
  Tissue samples were collected from 150 men who presented with clinical and laboratory data indicating NOA by means of TESE and micro dissection TESE methods. Initially, mature spermatozoa were examined for by mechanical extraction technique shredding the biopsy fractions. In cases whom no spermatozoa was observed after maximum 30 min of initial searching under the inverted microscope, the procedure was followed by enzymatic digestion using DNaseI and collagenase type IV. Surgery type, pathology, AZF, karyotype, hormones and testis size were compared in patients.
  
  
  RESULTS
  Of 150 cases with NOA, conventional mincing method extended with enzymatic treatment yielded successful sperm recovery in 13 (about 9%) patients. Comparison of parameters revealed that level of FSH and LH were significantly different (p=0.04 and 0.08 respectively) between two groups that response negative and positive to enzymatic digestion.
  
  
  CONCLUSIONS
  The combination of conventional TESE and enzymatic digestion is an effective method to recover spermatozoa. The benefit of the mincing combined with enzyme to sperm retrieval for NOA firstly shorten the mechanical searching time, leading to minimizing further cellular damage as well as exposure to external conditions, and secondly reduce the number of cases with sperm recovery failures. Also, the serum level of FSH and LH are factors that influence the chance of sperm retrieval.
authors.affiliation: Department of Andrology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Tahereh
authors.initials: T
authors.lastname: Modarresi
authors.affiliation: Department of Andrology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Sabbaghian
authors.affiliation: Department of Embryology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Abdolhossein
authors.initials: A
authors.lastname: Shahverdi
authors.affiliation: Department of Andrology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Hani
authors.initials: H
authors.lastname: Hosseinifar
authors.affiliation: Department of Epidemiology and Reproductive Health at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Akhlaghi
authors.affiliation: Department of Andrology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran. ; Department of Urology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Sadighi Gilani
keywords: Enzymatic digestion; FSH; LH; Non-obstructive azoospermia; TESE