Laser tissue welding - poised for the new millenium.

Laser tissue welding is a relatively new technique, which was initially described only about 30 years ago. Over the past 10 years, the implementation of protein solders has redefined the field. Alternative methods of wound closure and of tissue approximation have been quickly accepted in clinical medicine. The techniques and theory involved in performing laser tissue welding may soon be essential knowledge for all surgeons. Just as laparoscopy has become a mainstay for general surgeons and urologists, novel mechanisms of tissue approximation will continue to replace older, less efficacious techniques.

Preoperative screening for genetic abnormalities in men with nonobstructive azoospermia before testicular sperm extraction.

PURPOSE: Men with nonobstructive azoospermia may be treated with testicular sperm extraction and assisted reproduction. However, in men with severely impaired spermatogenesis genetic anomalies may be a cause of low sperm production. We present the results of genetic screening of men with nonobstructive azoospermia who are testicular sperm extraction candidates. MATERIALS AND METHODS: Genetic evaluation was performed in a sequential series of 190 men with nonobstructive azoospermia who were candidates for testicular sperm extraction, including standard peripheral karyotypic analysis and detailed polymerase chain reaction based evaluation of the Y chromosome. All men found to harbor genetic defects were referred for genetic counseling. RESULTS: Of the 190 patients 33 (17%) had genetic abnormalities. Of the 101 men who underwent karyotyping 21 (21%) had cytogenetic abnormalities, including 13 with Klinefelter's syndrome. Of the 183 men who underwent Y chromosome partial deletion analysis defects were detected in 17 (9%). Five men had karyotypic anomalies as well as evidence of partial Y chromosome deletions on polymerase chain reaction based analysis. Genetic counseling was done in 31 men with defects before testicular sperm extraction. Knowledge of the specific genetic defect resulted in a change of clinical management in 7 of the 33 couples (21%) in which the man had a genetic abnormality. CONCLUSIONS: These results indicate that preoperative genetic screening is important in men with nonobstructive azoospermia who are candidates for testicular sperm extraction with intracytoplasmic sperm injection. Genetic testing provides men with reassuring etiological information regarding the infertile condition as well as a means to assess the risk of passing infertility traits to male offspring. It allows specific preimplantation genetic testing of embryos during assisted reproduction to minimize the risk of transmitting genetic defects to offspring.

Successful use of undersized donors for orthotopic heart transplantation--with a caveat.

Accepted clinical practice has been to require body weights to be within 20% as a criterion for matching donor to recipient for cardiac transplantation. From November 1989 through September 1993 we began accepting larger differences in body weight between donor and recipient with 80 orthotopic heart transplants performed. Twenty-eight of these transplants used undersized donors (donor-to-recipient body weight ratio [DRBW] of 0.6 to 0.8) with the remaining donors being either size matched (DRBW = 0.8 to 1.0) or oversized (DRBW > 1.0). Thirty-three of the 80 transplant recipients (41%) were classified preoperatively as United Network for Organ Sharing (UNOS) status I and the remaining patients were classified as UNOS status II. Hospital survival for status I recipients was 9 of 14 (64%) for undersized donors, 7 of 8 (87.5%) for sized-matched donors, and 11 of 11 (100%) for oversized donors (p < 0.05). Hospital survival for status II recipients was 12 of 14 (85.7%) for undersized donors, 24 of 24 (100%) for sized-matched donors, and 8 of 9 (88.8%) for oversized donors. Our data support the continued use of hearts from undersized donors in status II recipients. The use of hearts from undersized donors in status I recipients is associated with increased mortality compared with size-matched donors and must be undertaken with caution.