Holmium Laser Enucleation of the Prostate: An Evolving Prostatectomy Technique

Laser prostatectomy has evolved in the last 2 decades to become a viable and competitive option for open simple prostatectomy and transurethral resection of the prostate to treat obstructive symptomatic benign prostatic hyperplasia. There are 2 laser prostatectomy procedures, one of which uses a pure vaporization/ablation technique in which tissue is vaporized away in a systematic sweeping fashion. With the other procedure the prostate is resected into small pieces with the aid of a laser and/or a mechanical morcellator. What is clear is that the second procedure is more technically challenging.

Each laser system has its own unique laser tissue interaction. With its high absorption characteristic in water, the effect of the holmium system is basically a high frequency thermo-mechanical pulse generated by absorption of laser energy in water resulting in a vaporizing water bubble that produces a hot explosion. These laser features are ideal for stone lithotripsy at a low pulse rate. However, at high frequency and power, they can vaporize tissue at near contact.

The holmium technique was initially applied as an ablating tool for holmium laser prostate ablation.1 However, it became apparent that it was not an efficient ablator since its thermo-mechanical effect was more suited to cutting tissue. Thus, holmium laser prostate ablation has been limited to small glands. This limitation led to holmium laser prostate resection, which is still tedious and difficult with an end-fire laser since the resected pieces need to be small for extraction and its vaporization effect is limited.

In the late 1990s the resection technique evolved to enucleation of the gland, which involved a combination of transurethral digital enucleation with the scope tip with laser cutting and coagulation, and mechanical morcellation of the large enucleated lobe that was pushed into the bladder.2 Initially, technically difficult and mastered at centers with surgeons dedicated to perfecting the technique, holmium laser prostate enucleation has slowly gained acceptance by other surgeons committed to the technique. During the last decade many randomized trials at these centers have demonstrated equivalent efficacy with superior safety over open prostatectomy and transurethral prostatic resection. It is still well acknowledged as a difficult procedure to master but the procedure is better defined and easier to teach as this month's video and study demonstrate.

In this issue of The Journal Dusing et al (page 635) describe the evolution of holmium over time by centers of excellence. The centers became more proficient in performing the procedure, improving on complications, reducing operative time and accomplishing better surgical debulking. To be precise, lasering time is not quite an accurate description since there is a fair amount of digital enucleation with the aid of the scope tip to accomplish enucleation versus a pure laser cut/vaporization of tissue. Additional time is still required for morcellation which in many randomized studies is associated with a small risk of bladder injury. Overall, however, holmium laser prostate enucleation has proved to be as efficacious and safer than open prostatectomy or transurethral prostatic resection.3 This month's video by one of the coauthors of this multicenter study demonstrates the key technical points of this technique, and provides a perspective that makes it easier to teach and acquire efficiency and proficiency (mms://media.auanet.org/SV080107).4

The pioneering work by holmium based surgeons has led to a trend of using a modified resection/enucleation technique with other laser systems such as the high power 532 nm laser system, which is the future in addressing large glands with challenging intravesical lobes.5 These large glands will always be technically challenging not because of the energy source used, but because of the more complex transurethral skill set required to resect/vaporize them and the associated difficult intravesical anatomy. As surgeons, we are still using a “knife on the end of the stick” technique to carefully resect these large prostates into pieces for extraction, thereby removing obstructive prostate tissue in an effort to treat symptomatic benign prostatic hyperplasia regardless of energy source.