An intricate procedure that finds and carefully removes individual sperm from testicular tissue has made fathers of men who were once considered sterile due to prior cancer treatment, say researchers at New York-Presbyterian Hospital/Weill Cornell Medical Center who pioneered the technique.

In the March 14 issue of the Journal of Clinical Oncology, the physician-scientists say 20 children have been born to the female partners of men who underwent the technique, known as microdissection testicular sperm extraction (TESE). After the sperm was taken from the tissue, they were injected into eggs that had been clinically removed from the women. Of the 73 men in the study, 15 became fathers.

The findings prove the value of this approach in helping men whose fertility had been compromised by chemotherapy treatment, says Dr. Peter Schlegel, chairman of the Department of Urology at Weill Cornell Medical College and urologist-in-chief at New York-Presbyterian Hospital/Weill Cornell Medical Center.

"These men were typically told by their doctors that they were sterile, and now some have a family," says Dr. Schlegel. "These are dramatic results when you consider that men normally make hundreds of millions of sperm cells every day. Using microTESE, we find, and take out, only a dozen or two sperm."

The technique was developed by a team led by Dr. Schlegel, who first published information about microTESE in 1999. After patients are given anesthesia, surgeons essentially operate inside the testes using a surgical microscope. The testicular tissue is microdissected until sperm is found. TESE is followed by immediate intracytoplasmic sperm injection (ICSI) into eggs to fertilize them.

The men treated in this study had all been treated with chemotherapy for a variety of cancers, including lymphoma (Hodgkin's and non-Hodgkin's), leukemia, testicular (germ cell) cancers and sarcoma. None had donated sperm to be frozen before treatment; in some cases the patients were prepubescent.

While chemotherapy regimens have attempted to reduce toxicity to the gonads as much as possible, up to two-thirds of patients are azoospermic after treatment. These men are told to consider adoption or use donor sperm.

Dr. Schlegel and his team adapted TESE/ICSI for chronically azoospermic patients and published the first results on 17 patients in 2001. This study now represents the largest series of postchemotherapy patients treated with TESE/ICSI, with a total of 84 TESE procedures performed between 1995 and 2009.

Sperm was successfully retrieved in 37 percent (27 of 73) of patients. In these patients, the fertilization rate was 57 percent per injected egg (198 out of 347 oocytes). Half of the women who received fertilized eggs became pregnant, and the live birth rate was 42 percent -- there were 15 deliveries with five twin births for a total of 20 healthy children.

The researchers found that patients who were treated for testicular cancer seemed to have the highest sperm retrieval rates (85 percent) despite having only one testicle. Patients with lymphoma had sperm retrieval rates of 26 percent to 36 percent, while sarcoma survivors had the lowest rates.

Dr. Schlegel says that depending on the type of chemotherapy and dose used, azoospermia, or absence of sperm, can affect up to 70 to 100 percent of treated patients. The risk of azoospermia for men treated with alkylating agents including cyclophosphamide, a common treatment for lymphoma, approaches 100 percent.

The researchers found that for patients treated with chemotherapy for lymphoma, the sperm retrieval rate was 33 percent, compared with 85 percent for patients treated for testicular cancer.

They also found that the children born to these men did not have birth defects, which is a concern that patients sometimes have, Dr. Schlegel says. He adds that several large studies on the children of men treated with chemotherapy have neither shown a higher rate of birth defects nor more childhood malignancy when compared with the general population.

"Our recommendation is that sperm banking be offered before any chemotherapy treatment in men, but when that is not done, or if the patients treated are too young to produce sperm, TESE offers some men fertility," says Dr. Schlegel.

The study was supported by a grant from the Frederick J. and Theresa Dow Wallace Fund of the New York Community Trust.

Dr. Schlegel's co-authors are Drs. Zev Rosenwaks, Wayland Hsiao, Peter Stahl, E. Charles Osterberg, Edward Nejat and Gianpiero Palermo, all from New York-Presbyterian/Weill Cornell.