Newly developed techniques in andrology: endoscopy of the vas deference and a new imaging technique for in situ localization of vital spermatozoa

Abstract

D uring the past decade, endourologyrepresents the most advanced technology in urology which has provided minimal invasive diagnostic and therapeutic tool for patients with urology diseases. However, because of the much smaller lumen of genital tract, endoscopic andrology remained a dream for andrologists until the first clinical application of vesiculoscopy in laser lithotripsy of seminal vesicle stones in 2006. Lately, Dr Trottmann at Ludwig-Maximilians University, Germany, for the first time established vasoscopy in the seminal duct using a new prototype of a microendoscope and also applied a new imaging technique for in situ localization of vital spermatozoa. These newly developed techniques will greatly speed up the clinical practice of endoandrology.With the development of modern science and technology, there are emerging and promising diagnostic and therapeutic tools for male fertility problems. Transurethral seminal vesiculoscopy is one of the advanced techniques, which has been proved safe and effective in the diagnosis and treatment of ejaculatory duct obstruction, seminal vesicle stones and refractory hemospermia. 1 However, to date, the endoscopy of the vas deference has not yet been achieved because of the small lumen of the seminal duct. As for nonobstructive azoospermia and surgically failed obstructive azoospermia, testicular sperm extraction (TESE) or microsurgical TESE is still the main option for assistant reproduction. The blindly extracted sperms still need to verify their viability ex vivo for the use in intracytoplasmic sperm injection. Up to now, there is no imaging technique in the testis which allows the detection of vital spermatozoa, therefore, to improve retrieval rate for the patients undergoing TESE.Based on the demanding of above clinical needs in andrology, Trottmann et al. 2 at Ludwig-Maximilians University, Munich, Germany established vasoscopy in the seminal duct using a new prototype of a microendoscope. For the first time, they reported a preclinical randomized study at the TwentyEighth Annual EAU Congress in Milan on 15-19 March 2013. The vas dereferences of transsexual men were investigated ex vivo after surgical removal. In a second step, the vas dereferences of men within 24-48 h after death were investigated in situ. For the experiments, a semirigid microendoscope of 0.6 mm outer diameter offering the possibility to insert 0.4 mm thick tools and with integrated fiberoptics (0.9 mm, 10 000 pixels) and a depth of field from 3 to 20 mm was used. After surgical removal, antegrade and retrograde views of the inner lumen of the vas deference were achieved. Using a working channel, a biopsy forceps and a laser fiber were introduced into the inner lumen allowing obtaining probe material and to close or open the lumen by coagulation and vaporization, respectively. The in situ investigations showed that transurethral endoscopy of the vas deference provided good images of the inner surface of the seminal duct up to the vesicular gland.As an emerging optical imaging technology, pro...