Lasers in Urology

Lasers in Urology

The extensive usage of small diameter endoscopic instruments and the recent improvements in fiber-optics and lasers has proved to be a perfect amalgamation in the field of urology. It has opened up new avenues for diagnosing various ailments afflicting the excretory system and exciting probabilities for treating them with minimal side-effects. Let us discuss the importance of lasers in the field of urology in detail.

Important Uses of Lasers in the Field of Urology

• For Cutting Soft Tissues like strictures on the neck of the bladder, urethral strictures, posterior urethral valves, etc. Lasers like Ho:YAG, KTP and Nd:YAG are generally used for this purpose.
• For Resection and Ablation of hemangiomata of bladder and skin, carcinoma of penis and in benign prostate hypertrophy (BPH). Nd:YAG, KTP:YAG and Ho:YAG lasers are usually used for these cases.
• For Lithotripsy: Lasers like Ho:YAG, FREDDY, pulsed dye, or alexandrite are used for treating stones in the bladder, renal pelvis and ureters.
• For Welding of Tissues: Lasers like diode, KTP, Nd:YAG, or CO₂ are used for treating hypospadias, urethral strictures and fistulas, increasing the size of the bladder, creating urinary diversion, etc.
• For Diagnosing bladder malignancies through autofluorecence, with the help of nitrogen laser.
• For Hair Removal from the perineal skin meant to be used as urethral grafts, with the help of lasers like ruby, alexandrite, diode, or Nd:YAG.

Use of Lasers in Urological Surgeries

Lasers are used in important surgeries of the excretory system. Some of them are:

• Urolithiasis

Stones of the renal pelvis, ureters and the bladder are often treated with the help of endoscopic intracorporeal lithotripsy. Using it in tandem with extracorporeal shockwave lithotripsy has made open surgery of urinary stones almost obsolete. Either retrograde ureteroscopy or percutaneous nephrostolithotomy are performed depending upon the location and the size of the stones. Laser energy is then delivered with the help of flexible fiber-optic endoscopes and the stones are fragmented into tiny pieces which are then flushed out with urine.

• Treatment of Benign Prostatic Hypertrophy

The two main methods by which BPH is treated are coagulation and vaporization. During coagulation, laser energy is used to heat up the prostatic tissue to temperatures as high as 100^oC.This causes denaturation of the proteins and necrosis of the tissue which ultimately sloughs off leading to de-bulking of the prostate gland. This process takes several weeks and the resultant edema may transiently increase the volume of the gland.
During vaporization, laser energy directed at the prostate tissue may lead to temperatures as high as 300^oC. The water in the tissue vaporizes leading to instant de-bulking of the prostate gland.
The major problem while using lasers to treat BPH is the fact that prostate tissue cannot be obtained for biopsy.

• Treatment of Urothelial Malignancies

Various types of lasers like Nd:YAG and holmium are used for treating tumors of the bladder and upper urinary tract. They can coagulate and ablate the tumor tissue with precision and their effect extends deeper than other types of laser energies. As the bleeding is less, post-operative catheter drainage is not required. Incidence of stricture formation is much less as compared to electro-cautery and there is no need of anesthesia.

• Treatment of Urothelial Strictures

Ho:YAG is used to treat obstructions of the uretero-pelvic junction, contractures at the neck of the bladder and posterior urethral valves. This type of laser energy is preferred as it is more precise, safe, has superior cutting ability and inflicts minimal collateral damage.

• Ablation of skin Lesions

CO₂ laser is used to treat superficial lesions of Condyloma acuminate, a sexually transmitted disease which involves the penile shaft, glans and urethra. Nd:YAG and KTP lasers are used for treating deeper lesions. Nd:YAG laser gives excellent cosmetic results when used in the treatment of carcinoma of penis in early stages. Similarly, cutaneous hemangiomas of penis and scrotum can be successfully treated with lasers.
 
Reference:
“Lasers in urology,” by Bhatta K.M. Published in October 2005 in the journal Lasers in Surgery and Medicine, accessed on June 24, 2015. Retrieved from:
https://onlinelibrary.wiley.com/doi/10.1002/lsm.1900160403/pdf