Photoselective Vaporesection of the Prostate via an End-firing Lithium Triborate Crystal Laser

Summary

Here we present a protocol to perform Photoselective Vaporesection of the Prostate (PVRP) for benign prostatic hyperplasia (BPH) treatment.

Abstract

The occurrence of lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) is a common problem with a high incidence in the aging male population. Although it is not a life-threatening disease, BPH causes problems that seriously impact the quality of life. Here, we introduce a new technique called photoselective vaporesection of the prostate (PVRP) in treating BPH, which can be seen as a variation of photoselective vaporization of the prostate (PVP). This procedure presents several advantages compared to the PVP technique including less laser energy loss, less intraoperative complications as well as more tissue resection rate.

Introduction

Although transurethral resection of the prostate (TURP) is still accepted as the gold standard in benign prostatic hyperplasia (BPH) surgical treatment, laser surgeries have gradually become more popular due to the better patient tolerance, less intraoperative blood loss, satisfactory efficacy, and shorter postoperative recovery^1,2,3. Currently, the most commonly used lasers for the BPH treatment worldwide are generated by lithium potassium titanyl phosphate or lithium triborate (LBO) crystals^4,5. Traditionally, these are classified as sidefiring lasers compared to other types of laser, such as holmium laser and thulium laser.

Photoselective vaporization of the prostate (PVP) surgery could considerably decline TURP syndrome due to saline irrigation^6,7, and compared to other types of lasers, the reliable efficacy of lower urinary tract syndrome (LUTS) by PVP was verified by a series of studies^8,9,10. However, PVP associated with side-firing laser emission also has some disadvantages, including an energy loss of nearly 20% and a short lifespan of the laser fiber^11,12,13. Moreover, PVP increases the possibility of missed diagnosis of prostate cancer due to complete tissue vaporization.

The introduction of Photoselective Vaporesection of the Prostate (PVRP) with an end-firing fiber successfully overcame most of the disadvantages of PVP mentioned above. First, the tip is capable of transmitting laser to the tissues with almost no energy loss intraoperatively. Second, when fiber debris collects on the tip, it is straightforward to maintain the ideal output power by simply removing the affected parts. Finally, laser resection enables the collection of specimens for postoperative pathologic examination. Hence, using this protocol in treating BPH could enhance the tissue removal rate, save the operative time and improve the intraoperative safety.

Protocol

All methods described here have been approved by ethics committee of Beijing Hospital. Indications for surgery are according to the European Association of Urology guidelines for nonneurogenic male LUTS. Contraindications include suspected prostate cancer or detrusor dysfunction.

1. Instruments for Operation

1. Ensure the availability of a LBO crystal laser with a maximum power of 160 W.
2. Employ an endfiring laser fiber and saline solution for intraoperative bladder irrigating.
3. Use a 26F laser resectoscope to acquire good vision and to enhance the resection efficiency.

2. Preparation for Operation

1. Provide an intravenous antibiotic preoperatively (intravenous administration of cefuroxime sodium 1.5 g with 100 mL 0.9%sodium chloride solution 30 min before the operation) to all the patients.
2. Before the anesthesia, make the patient lay down on the operation table.
   Note: General anesthesia is effective and appropriate for this operation, Anesthetist will finally determine the mode of anesthesia depending on patient's general condition.
3. Drape the patients in a sterile fashion in the dorsa lithotomy position.Do not perform any skin preparation.

3. Procedure Steps

1. Vaporesection of the Median Lobe
   1. Examine the whole bladder cavity and prostatic urethra carefully through the resectoscope after the bladder is distended.
      Note: This step helps urologist to locate some key anatomic sings including bilateral ureteral orifice and verumontanum.
   2. Mark two lines initially. Ensure that these lines originate at 5 o'clock and 7 o'clock at the bladder neck and continue along the boundaries between the median and lateral lobes, finally terminating at the proximal margin of the verumontanum.
   3. Set laser power at 80 W. Vaporize the prostate tissue via a fiber by the laser vaporization along these lines until the white cyclic fibers are seen.
      Note: This is the sign of prostatic capsule. The two lines are merged into single line adjacent to the verumontanum.
   4. Set laser power at 80 to 100 W. Mark several lines on surface of the middle lobe via laser fiber. Then divide the wedgeshaped middle lobe into several chunks according to these lines through vaporization technique. Then split each chunk from the middle lobe. Finally, remove the whole middle lobe.
2. Vaporesection of the Lateral Lobes
   1. Vaporize the tissue at 12 o'clock from the apex of the prostate to the bladder neck by rotating the cystoscope 180°. Do not let the laser fiber go too close to the apex at 12 o'clock which can cause postoperative urine incontinence.
      Note: This technique enhances the resection rate of the tissue around the prostate roof.
   2. Identify the lower margin of both the lateral lobes clearly once vaporesection is complete.
   3. Before removing the lateral lobes, set another 2 similar grooves that originate from the bladder neck at 3 o'clock and 9 o'clock to the proximal end of the verumontanum.
   4. Remove the tissue of the lateral gland. Set the laser power at 80 to 100 W and mark several lines on the surface of the left lobe via laser fiber that divides the left lobe into several chunks according to these lines through vaporization technique. Then split each chunk from the lobe and finally remove the whole left lobe. Repeat this procedure to remove right lobe.
   5. Remove the remnant gland tissue along the existing boundary of the capsule.
3. Channel Trimming
   1. Remember to trim some protruding tissues around the apex of the gland, to enhance the integrity of the cavity.
   2. To avoid intraoperative complications (i.e., capsule perforation or sphincter injury), use vaporization technique rather than resection to trim the tissue near the external urethral sphincter and lower the power to less than 80 Watt.
4. Hemostasis and Catheterization
   1. Employ a glass syringe that matches the interface of the resectoscope to remove tissue chunk by water flow. Make sure there is no evidence of the residual tissue in the bladder and prostatic fossa through resectoscope, and identify the intact of the ureteral orifices.
   2. Employ a lower laser power (30 to 50 W) to stop bleeding around the surgical site. Keep an appropriate distance usually 3 to 5 mm between fiber and vessels to acquire a satisfying hemostasis effect.
   3. Remove the resectoscope from the urethra. Place a 22 French Foley catheter from urethral orifice to bladder cavity gently with 30 mL water in the balloon after sufficiently lubricating urethra by lidocaine gel.
5. Postoperative Care
   1. Let the patient lay down on the bed for around 3 h postoperatively in the care unit until they completely wake up from anesthesia. Meanwhile, make sure patient monitors and medical oxygen are available during this time.
   2. Upon completely waking up, return the patient to the ward. Let the patient begin to drink some water and take some food. Record the urine output and pay attention to the color of the urine.

Results

A total of 35 patients who underwent PVRP were included in one of our studies. The mean patient age was 72.1 ± 7.1 years (range 53-85 years).

Perioperative data are listed in Table 1. The mean laser emission time accounted for nearly 50% of the mean operative time. The blood loss in most patients was < 200 mL. However, the average deviated due to some moderate bleeding cases. Almost 90% of the patients ...

Discussion

Here, we share our experiences with PVRP. First, PVRP enabled better exposure of the prostate capsule with proper demarcation and reduced the risk of capsule perforation. Second, the tissue removal should be carried out along the surgical capsule, especially with the groove at 12 o'clock, which facilitates tissue resection around the roof of the prostatic urethra and provides a satisfactory tissue removal rate. Third, it is essential to remove the middle lobe initially to acquire a wider channel in the prostatic uret...

Materials

Name	Company	Catalog Number	Comments
FLARE surgical Laser Fiber	REALTON		The FLARE Surgical laser Fiber is a 600 micron fiber with an straight tip that transmits the laser energy directly. this product is packaged sterile for disposable use and should not be re-sterilized or reused. Dispose of properly after use.
AURORA Surgical Green Laser System	REALTON	pvp-160-021	The AURORA Surgical green laser system is a diode-pumped, frequency-doubled Nd:YAG solid state laser. The AURORA Surgical green laser system features a “Plug and Play” capability that self-adjusts to the facility’s individual voltage requirements, eliminating the need for electrical modifications. The laser system also includes an air-cooled internal mechanism, ensuring safe operating temperatures with no external water connections. Laser energy emission and system status selection is activated through a surgeon-controlled, color-coded footswitch or system touch screen feature located in the laser console.