Holmium Laser Prostatectomy
Content by Mr Rick Popert
The Holmium Laser is a powerful surgical tool and is the most versatile of urological surgical lasers. It can be used to treat all sizes of prostate as well as all types of urinary tract stones anywhere within the urinary tract, bladder tumours, strictures and post radiotherapy bleeding. It is most commonly used to treat patients presenting with bladder outflow obstruction and is the most effective way to remove the obstructing prostate tissue. Patients will present with moderate to severe lower urinary tract symptoms. There is typically a history of hesitancy, poor urinary flow, incomplete bladder emptying, post void dribbling and frequent visits to the toilet at night. Most patients will have received treatment with medication to relax the smooth muscle of the prostate and the bladder neck, an alpha blocker, such as Tamsulosin (Flomax) or Alfusosin (Xatral) or to shrink the prostate, a 5 alpha reductase inhibitor, such as Finasteride (Proscar) or Dutasteride or in combination as Combodart.
The urinary flow rate will typically show a prolonged void with a maximum flow of less then 10 ml/s. An ultrasound will often document a residual urine and an enlarged prostate.
Fig 1 : Pre Operative Urinary Flow Rate
The endoscopic appearances of the prostate will show occlusive enlargement of the middle and lateral lobes responsible for the physical obstruction experienced by the patient. It is this central portion of the prostate which has to be removed.
Fig 2 : Enlarged prostate with ball valving middle lobe.
The final appearances 6 weeks post operatively demonstrate a large cavity in which all of this central tissue has been removed.
Fig 3 : Post Operative appearance at 6 weeks
Patients prostate symptom scores dramatically improve after surgery consistent with the objective improvement in the urinary flow rate.
Fig 4 : Post Operative Urinary Flow Rate at 6 weeks
My experience with the Holmium laser has been very encouraging and has included over 1000 patients since 2003. It has allowed me to treat patients who would otherwise be considered unfit for prostate surgery and particularly those with very large prostates, who ordinarily would require open surgical removal with a painful wound and prolonged inpatient stay. There is no need for patients to stop aspirin preoperatively and I have treated patients on anticoagulants and haemophiliacs without any need for transfusion. As my experience has grown I have been able to treat progressively larger prostates, sizes up to 150 cc are common with some even larger. The normal prostate size is around 30 cc and so many of these patients have prostates that are between 5 or 10 times the average size. Although the procedure may takes much longer with operating times of 2 – 3 hours there are very significant advantages over traditional TURP or open surgery. Firstly one can achieve complete clearance of the central enlargement of the prostate; secondly the procedure is very safe with reduced risk of significant bleeding; the need for blood transfusions is very low, fluid absorption (a problem in TURP); a short catheter time combined with a reduced length of inpatient stay.
In general, catheters are removed early the next morning and most patients discharged within 24 hours of surgery. Patients with larger prostates, the elderly and those on anti-coagulants tend to stay a little longer. There is an immediate improvement in the urinary flow, with only mild discomfort, which compares favourably with TURP and other laser techniques such as Green Light PVP laser.
Why is an MRI recommended before HoLEP ?
An MRI scan is a very useful imaging tool to evaluate the anatomy of the prostate in the planning of surgery. It provides the surgeon with a detailed representation of the size of the prostate and the interrelationship of the middle and lateral lobes of the prostate. An accurate assessment of the size of the prostate is important when planning the time to be taken for an individual’s procedure. The detailed anatomy can be very helpful when planning the surgical approach and also provide landmarks to ensure full enucleation of the adenoma.
More importantly the MRI scan is very helpful in delineating the benign transition zone from the outer peripheral zone. Specifically the MRI images may identify an area of abnormality within the prostate peripheral zone (the outer rim) which might be suspicious for prostate cancer. It is important to exclude significant prostate cancer before carrying out a HoLEP procedure, particularly in men under the age of 70, because more definitive surgery or treatment to the whole gland may be necessary. If the MRI does identify a suspicious lesion then targeted biopsies of the abnormal area and, if necessary, systematic biopsies to the rest of the peripheral zone are recommended.
Fig 5 : MRI Scan of very large 150 cc prostate BEFORE HoLEP
Note the thinned outer peripheral zone on the left (like a pair of bull’s horns) with enlarged central transition zone, which is obstructing the urinary flow.
Impact of HoLEP on PSA Test & the Resolution of Uncertainty
Most patients with a very large prostate of 100 – 150 cc will have a PSA blood test of between 10 and 15 ug/l. All of these people (and their doctors) will have had concerns about their individual prostate cancer risk. Often they have had 2 or 3 sets of trans rectal prostate biopsies, some complicated by sepsis, because of this uncertainty. The problem with the PSA test is that it is Prostate Specific Antigen not Prostate Cancer Specific Antigen.
As a urologist involved in the diagnosis and treatment of prostate cancer, one of the most significant benefits I see for patients is how HoLEP can resolve the uncertainty of the PSA blood tests in the prostate cancer diagnostic pathway.
The prostate gland is comprised of an outer peripheral zone (where 96% of cancers develop) and a more central transition zone, the part of the gland that gets bigger as one gets older, causing the urinary symptoms associated with prostate enlargement. This predominantly benign transition zone contributes significantly to the raised PSA level in many patients with prostate enlargement.
Fig 6 : MRI Scan of prostate AFTER HoLEP with a volume of 20 cc
Note the residual outer peripheral zone and the dramatic reduction in size from removal of the central transition zone and the cavity within the prostate.
The HoLEP procedure is an effective method to remove the majority of the transition zone. The final histology invariably reveals benign tissue and the PSA blood test falls to very low levels after surgery, (usually less than 1 ug/l).
If the PSA does not fall to a very low level after HoLEP it is because either there is some residual benign prostatic tissue or because there is some unrecognised sinister change within the remaining peripheral zone of the prostate. In patients on Acive Surveillance HoLEP provides an excellent method for normalising the PSA and reassuring both the patient and his doctor.
Fig 7 : Dramatic change in median PSA before and after HoLEP
Holmium Laser Ablation (HoLAP) is an alternative to Enucleation and Morcellation. It was the forerunner of enucleation and was first described by Messrs Fraundorfer & Gilling in 1994. The procedure is technically identical with the PVP or Green Light Laser in which a side fire laser carrier allows the laser energy to be applied directly on to the prostate tissue, vapourising it. The vapourisation or ablative approaches have been of limited use in the past and it has only been with the development of more powerful lasers (120 watt) that it has become a practicable procedure. Vapourisation seems a useful technique which can be applied to smaller prostates, it is less demanding surgically, it creates a reasonable cavity. It appears to be a good way for surgeons to progress from the Green Light laser to the more technically demanding HoLEP procedure.
The rapid progress in laser prostatectomy technology and techniques over the last few years are challenging the place of TURP as the gold standard operation for patients with bladder outflow obstruction. It works very well.