0022-5347/00/1632-0515/0 THE JOURNAL OF UROLOGY® Copyright © 2000 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 163, 515–518, February 2000 Printed in U.S.A.
TRANSURETHRAL HOLMIUM LASER RESECTION OF THE PROSTATE KEI MATSUOKA, SHIZUKA IIDA, KATSURO TOMIYASU, AKIHIKO SHIMADA
From the Department of Urology, Kurume University School of Medicine, Kurume, Fukuoka, Japan
Purpose: We evaluated the efficacy of the holmium:YAG laser for transurethral endoscopic prostatectomy for benign prostatic hyperplasia (BPH). Materials and Methods: We treated 103 patients with BPH with holmium:YAG laser resection of the prostate. A high power holmium laser generating a maximum of 60 or 81 W. was used in a pulsed mode, applying energy directly to prostatic tissue via a forward firing 550 m. fiber transurethrally under direct vision. Treatment outcome was evaluated by the International Prostate Symptom Score, quality of life score, maximum flow rate and post-void residual urine volume. We also compared holmium laser surgery and transurethral resection of the prostate for operative factors, such as surgical duration, bleeding volume and catheterization time. Results: Average symptom score, quality of life score, peak flow rate and post-void residual significantly improved at 1 week, 1 month and 3 months postoperatively, with improvement maintained up to 36 months postoperatively in the holmium:YAG group. Intraoperative bleeding volume was significantly lower and catheterization time was significantly shorter for holmium:YAG than for transurethral prostatic resection. Use of the holmium laser caused no complications. Conclusions: Because of its effectiveness and safety holmium:YAG resection is a viable potential surgical alternative for symptomatic BPH. The holmium:YAG laser has been verified to be useful for many purposes in urology. KEY WORDS: prostatectomy, lasers, prostatic hyperplasia, prostate
The usefulness of transurethral surgery procedures for benign prostatic hyperplasia (BPH), including transurethral resection of the prostate,1, 2 transurethral ultrasound guided laser induced prostatectomy,3 visual laser ablation of the prostate, 4, 5 interstitial laser coagulation of the prostate6 and transurethral electrovaporization of the prostate,7 has been widely discussed. Most laser surgery is performed with the neodymium:YAG laser. Due to laser properties significant time is required for surgical effects to become apparent. The holmium:YAG laser is used for ablation, vaporization and coagulation, and is applicable to hard8 –10 and soft11–13 tissue. Its wavelength of 2,100 mm. penetrates soft tissue only 0.4 mm.14, 15 The laser affects only the visible area, enabling it to be used safely. The first attempts to use the holmium:YAG laser for transurethral prostatectomy were made by Gilling16 –18 Kabalin19, 20 and Fraundorfer21 et al. The new procedure was attractive and exciting, since a transurethral resection-like cavity was made in the prostatic urethra immediately after the procedure.22 Significant improvement in subjective and objective symptoms, with minimum morbidity, was also reported.23, 24 Our excellent early clinical results with holmium:YAG laser prostatic resection were reported in 1995,22 and we now present our relatively longterm followup results. SUBJECTS AND METHODS
Holmium:YAG resection of the prostate was sequentially performed on 103 patients with BPH at Kurume University Hospital between July 1995 and December 1998. All patients were diagnosed based on measurement of serum prostate specific antigen (PSA), digital rectal examination and transrectal ultrasonography. Transrectal biopsy of the prostate was done only on patients with abnormal findings. Patients were included in the study when prostate enlargement was benign and there was at least 1 positive preoperative assessment, that is International Prostate Symptom Score (I-PSS) Accepted for publication September 17, 1999.
score 8 or greater, maximum flow rate 15 ml. per second or less and post-void residual urine 50 ml. or greater. A modified endoscope with a continuous irrigation system was equipped with a device for fixing the laser fiber at the tip. Room temperature physiological saline was used for irrigation. A laser system which emits holmium:YAG and neodymium:YAG lasers was used and forward firing laser fiber was applicable to both with a diameter of 550 m. Laser power settings were 2.4 J. per pulse, 25 pulses per second and 60 W. for the first 60 cases, and 2.7, 30 and 81, respectively, for the last 43. The prostate was resected to form an effective cavity for voiding in the prostatic urethra (see figure), and incised at the 5 o’clock position from the bladder neck to the verumontanum to the base of the bladder using the left ureteral orifice as a landmark. A similar incision was made at the 7 o’clock position using the right ureteral opening as a landmark. The median lobe was resected with a transverse incision between the aforementioned 2 incisions. The transverse incision was started at the verumontanum and continued under the median lobe along the capsule toward the bladder neck, using the verumontanum as a landmark, and then the resected tissue was floated in the bladder. The incision at the 5 o’clock position was extended upward along the left lateral wall. When this upward incision reached the 3 o’clock position, a downward incision was added at the 1 o’clock position along the lateral wall. The left lobe was then resected and floated in the bladder. The right lobe was resected similarly. The incision at the 7 o’clock position was extended upward to the 9 o’clock position and then a downward incision was added at the 11 o’clock position. If the prostate was greatly enlarged, segments were made during these procedures so that resected tissues could be removed easily from the bladder. Resected tissue was removed using a modified loop and/or syringe. It was confirmed that neither residual tissue remained in the bladder nor bleeding occurred at incision sites. An 18Fr Foley catheter was left in the bladder and removed
HOLMIUM LASER RESECTION OF PROSTATE
Incision lines for holmium:YAG laser prostatic resection. A, median lobe resection starts at 5 o’clock (7 o’clock) position with incision performed from bladder neck toward verumontanum reaching base of bladder (line 1). Median lobe was removed by transverse incision along line that combines incision lines at angles of 5 and 7 o’clock positions starting from verumontanum toward cervical region (line 2). B, for lateral lobe resection incision was performed upward along line at angle of 5 o’clock (7 o’clock) position along lateral wall and then switched downwards at angle of 1 o’clock (11 o’clock) position (line 3). Left (right) lobe was removed by repeating dissections and removed pieces floated inside bladder.
the following morning or 2 days later if there was no macroscopic hematuria. If the patient complained of retention after the Foley catheter was removed temporary 1-day catheterization was performed once or twice. If this procedure was unsuccessful, a Foley catheter was reinserted and again removed the following day. Preoperative and postoperative I-PSS, quality of life score, peak flow rate and post-void residual measured 1 week, 1 month, 3 months, 6 months, 1 year, 2 years and 3 years after holmium:YAG surgery were compared. Holmium:YAG energy consumption was evaluated. Surgical duration, bleeding volume based on the amount of hemoglobin in irrigation fluid, amount of resected tissue and postoperative catheterization time in patients treated with holmium:YAG were compared to those in 152 patients treated with transurethral prostatic resection. Both groups were treated at our hospital by one of us (K. M.) but not concurrently. All transurethral prostatic resections were performed before holmium:YAG procedures. The initial prostate volume was estimated by transrectal ultrasound.25 Measurement of intraoperative blood loss was calculated by hemoglobin concentration in the irrigation fluid.26 Catheterization time includes total catheter time and re-catheterization. Data were analyzed using an unpaired t test and Dunnett’s multiple comparisons.27 RESULTS
No severe bleeding requiring blood transfusion occurred during holmium:YAG surgery. Slight bleeding from the mucous occurred in some patients with an enlarged prostate and occasionally disturbed the operative view when irrigation was insufficient. Under sufficient irrigation, mucosal bleeding caused no problems during surgery. In 3 of the 103 holmium laser treated cases transurethral surgery was repeated because of severe urinary retention after removal of the Foley catheter (1) and dysuria due to bladder neck con-
tracture (2). Repeat holmium laser procedures were performed on 2 patients and conventional transurethral prostatic resection was performed on the patient with urinary retention who did not elect to undergo another laser procedure. I-PSS score, quality of life score, peak flow rate and post-void residual significantly improved 1 week after holmium laser surgery (p ,0.0001) and continued for approximately 3 years (table 1). No local or systemic complication due to the use of the holmium:YAG laser occurred during or after surgery. We noted no hyponatremia, which sometimes occurs with transurethral prostatic resection, in patients treated with holmium:YAG laser surgery. There were no significant differences in mean age and mean estimated prostatic volume for the 100 holmium:YAG and the 152 transurethral prostatic resection treated patients. Average duration of holmium laser surgery was 81 minutes, which included the time required for endoscopic observation before resection and for removal of resected tissue from the bladder. Average volume of bleeding during laser surgery was 54.5 ml. and average amount of resected tissue was 8.3 gm. Average catheterization time was 2.8 days, which included the time required for re-catheterization in patients due to urinary retention after removal of the initial catheter. Average operative time for transurethral prostatic resection was 58 minutes. Average amount of tissue resected transurethrally was 20 gm. and average volume of bleeding during surgery was 336 ml. Average catheterization time was 4.9 days. There was a significant difference in average operative times for holmium:YAG surgery and transurethral prostatic resection (p ,0.0001). Average amount of resected tissue, volume of operative bleeding and catheterization time were greater for transurethral prostatic resection (p ,0.0001, table 2). Although the operative time was the same for the initial cases treated with the 60 W. and those treated with the 81 W. power setting, estimated prostate volume and weight of resected tissue for the latter were much greater. The bleeding volume and catheterization time for the 81 W. treated group were also much greater. However, these differences were not significant (table 2). DISCUSSION
Although visual laser ablation of the prostate using the neodymium:YAG laser is safe and simple to perform, its effects are not experienced immediately after surgery4, 5, 28 and may cause long-term inconvenience to patients. We focused on the holmium:YAG laser, which has coagulation as well as ablation and vaporization capabilities, and evaluated its application to the treatment of BPH. The active medium for the holmium:YAG laser is a crystal doped with holmium ions (Ho31). It is a pulsed laser with a wavelength of 2,100 nm. Ablation capability is similar to that of a carbon dioxide laser and coagulation capability is similar to that of a neodymium:YAG laser.11, 12 We first confirmed that the holmium:YAG laser is clinically applicable to endoscopic lithotripsy.10 The laser crushed cystine calculi for which a pulsed dye laser is not effective. Moreover, the target calculi moved little during holmium:YAG lithotripsy. The laser can efficiently and safely crush calculi
TABLE 1. Changes in assessment parameters following holmium laser resection of the prostate Mean 6 SD Preop.
No. pts. 100 82 78 64 58 I-PSS score 21.7 6 8.6 10.1 6 5.9 7.0 6 5.1 4.7 6 3.8 4.6 6 3.9 Quality of life score 4.8 6 1.1 2.2 6 1.7 1.6 6 1.2 1.4 6 1.1 1.4 6 1.1 Max. flow rate (ml./sec.) 7.3 6 3.9 13.6 6 6.0 15.7 6 6.5 16.3 6 6.9 15.7 6 6.4 Post-void residual urine (ml.) 137.0 6 136 41.0 6 54.0 37.6 6 33.3 22.7 6 16.2 34.0 6 30.0 All postoperative parameters were significantly improved (Dunnett’s multiple comparisons p ,0.0001).
54 5.1 6 4.0 1.4 6 1.2 17.8 6 6.5 24.0 6 19.8
32 5.0 6 4.7 1.3 6 1.1 16.8 6 5.1 22.3 6 19.3
11 4.3 6 1.6 1.2 6 0.4 17.8 6 5.2 35.6 6 20.1
HOLMIUM LASER RESECTION OF PROSTATE TABLE 2. Comparative surgical factors between holmium laser and transurethral resection of the prostate Mean 6 SD No. Pts. Age (yrs.) Laser surgery 100 Transurethral resection 152 60 W. group 60 81 W. group 40 * Significant difference compared
Estimated Prostate Surgical Duration Resected Tissue Bleeding Vol. Energy (kJ.) Vol. (ml.) (mins.) Wt. (gm.) (ml.)
70.2 6 7 37 6 20 129.4 6 63 83 6 35* 72.7 6 8 37 6 17 — 58 6 32 69.8 6 7 35 6 19 114.6 6 44 83 6 33 70.6 6 7 40 6 23 152.8 6 80 83 6 38 to transurethral resection (unpaired t test, p ,0.0001).
provided that the tip of the fiber does not touch the ureter wall. We then considered the holmium:YAG laser for BPH to maximize ablation and coagulation capabilities. Gilling16 –18 and Kabalin19, 20 et al reported excellent results for prostatic resection using the holmium:YAG laser and, therefore, we used the same method. We confirmed coagulation as well as vaporization and incision capabilities. When the laser was emitted from a laser fiber in contact with tissue, the tissue was vaporized and ablated. The coagulation capability of the laser was confirmed by emitting the laser 2 to 3 mm. away from a bleeding site. The system was equipped with holmium:YAG and neodymium:YAG laser sources but we seldom used the latter and only in case of severe bleeding. No arterial bleeding occurred, even when the prostate was incised at the 5 and 7 o’clock positions. Although slight bleeding occurred when the prostate was enlarged and the distal edge of the lateral lobe was resected, we were able to control the bleeding using the holmium:YAG laser alone. The bleeding volume during holmium laser surgery was much less than that during transurethral prostatic resection and postoperative bleeding was mild. Thus, an indwelling catheter for irrigation after surgery was unnecessary and bleeding was readily controlled without compression hemostasis with a tagged indwelling catheter. In most patients macroscopic hematuria disappeared 2 to 3 hours after surgery and, thus, we were able to remove the Foley catheter the following morning. However, 11 patients needed re-catheterization due to the onset of urinary retention after removal of the initial catheter, which resulted in an average duration of postoperative catheter drainage of 2.8 days. Average amount of tissue resected during holmium:YAG surgery was 8.3 gm., whereas the amount during transurethral prostatic resection was 20 gm. The actual amount of tissue resected during laser surgery would be approximately 33 gm. because measurements did not include the vaporized tissue, which was reported to account for 75% of the total amount of resected tissue.17 Symptoms improved satisfactorily and all postoperative parameters were significantly better than preoperative parameters for up to 3 years. We compared holmium:YAG and transurethral prostatic resection only in terms of technical and not postoperative parameters since this was not a comparative study of clinical effectiveness. However, in a randomized study Gilling et al showed that holmium:YAG and transurethral prostatic resection have similar postoperative outcomes, although perioperative results favor the former in terms of bleeding and catheter time.18, 29 Postoperative catheterization time was shorter for patients treated with the holmium:YAG laser but average operative time was prolonged. Possible reasons for the prolonged procedures were the extra time required for removal of resected tissues from the bladder and technical skill needed to resect the distal edge of the prostate using the forward firing fiber. Although holmium:YAG surgery may require knowledge and experience with transurethral prostatic resection, it seems to be easier for beginners to learn because operative bleeding is rare and hyponatremia is unlikely to occur when physiological saline is used for irrigation. We use physiological saline for holmium:YAG procedures, unlike transurethral prostatic resection or electrova-
8.3 6 6.3* 20.0 6 16.5 7.2 6 5.9 9.9 6 6.5
54.5 6 51.2* 336 6 325 23.9 6 22.7 64.7 6 79
Catheterization (days) 2.8 6 2.7* 4.9 6 2.8 2.4 6 2.9 3.5 6 2.3
porization, which is an advantage of laser surgery. We attempted to shorten operative time using the higher power settings of 81 W. Higher power appears somewhat useful in shortening the operative time but results were not significant, and now we are using the 1,000 mm. laser fiber to achieve shorter operating times. The duration will be further shortened through the use of a morcellator which is being developed to remove resected tissue from the bladder mechanically.30 As with transurethral prostatic resection, holmium:YAG surgery can be performed on lesions which can be reached with an endoscope. The largest volume of a prostate treated with holmium laser surgery in our study was 108 ml. It is anticipated that this volume will increase along with the learning curve as well as with improvement in devices. CONCLUSIONS
Holmium:YAG surgery caused little bleeding and achieved favorable improvement in patients with BPH 1 week after surgery. The procedure was safe with no serious complications in our series. Although holmium:YAG surgery needs further followup study, it is effective for BPH. Demetrius H. Bagley provided constructive criticism of the manuscript. REFERENCES
1. Holtgrewe, H. L. and Valk, W. L.: Late results of transurethral prostatectomy. J Urol, 92: 51, 1964 2. Melchior, J., Valk, W. L., Foret, J. D. et al: Transurethral prostatectomy: computerized analysis of 2,223 consecutive cases. J Urol, 112: 634, 1974 3. McCullough, D. L., Roth, R. A., Babayan, R. K. et al: Transurethral ultrasound guided laser-induced prostatectomy: national human cooperative study results. J Urol, 150: 1607, 1993 4. Kabalin, J. N.: Laser prostatectomy performed with a right angle firing neodymium:YAG laser fiber at 40 watts power setting. J Urol, 150: 95, 1993 5. Kabalin, J. N., Bite, G. and Doll, S.: Neodymium:YAG laser coagulation prostatectomy: 3 years of experience with 227 patients. J Urol, 155: 181, 1996 6. Muschter, R. and Hofstetter, A.: Interstitial laser therapy outcomes in benign prostatic hyperplasia. J Endourol, 9: 129, 1995 7. Kaplan, S. A. and Te, A. E.: Transurethral electrovaporization of the prostate: a novel method for treating men with benign prostatic hyperplasia. Urology, 45: 566, 1995 8. Sayer, J., Johnson, D. E., Price, R. E. et al: Ureteral lithotripsy with the holmium:YAG laser. J Clin Laser Med Surg, 11: 61, 1993 9. Denstedt, J. D., Razvi, H. A., Sales, J. L. et al: Preliminary experience with holmium:YAG laser lithotripsy. J Endourol, 9: 255, 1995 10. Matsuoka, K., Iida, S., Nakanami, M. et al: Holmium:yttriumaluminum-garnet laser for endoscopic lithotripsy. Urology, 45: 947, 1995 11. Johnson, D. E., Cromeens, D. M. and Price, R. E.: Use of the holmium:YAG laser in urology. Lasers Surg Med, 12: 353, 1992 12. Johnson, D. E., Cromeens, D. M. and Price, R. E.: Transurethral incision of the prostate using the holmium:YAG laser. Lasers Surg Med, 12: 364, 1992
HOLMIUM LASER RESECTION OF PROSTATE
13. Razvi, H. A., Chun, S. S., Denstedt, J. D. et al: Soft-tissue applications of the holmium:YAG laser in urology. J Endourol, 9: 387, 1995 14. Nishioka, N. S. and Domankevitz, Y.: Reflectance during pulsed holmium laser irradiation of tissue. Lasers Surg Med, 9: 375, 1989 15. Nishioka, N. S., Domankevitz, Y., Flotte, T. J. et al: Ablation of rabbit liver, stomach, and colon with a pulsed holmium laser. Gastroenterology, 96: 831, 1989 16. Gilling, P. J., Cass, C. B., Malcolm, A. R. et al: Combination holmium and Nd:YAG laser ablation of the prostate: initial clinical experience. J Endourol, 9: 151, 1995 17. Gilling, P. J., Cass, C. B., Cresswell, M. D. et al: Holmium laser resection of the prostate: preliminary results of a new method for the treatment of benign prostatic hyperplasia. Urology, 47: 48, 1996 18. Gilling, P. J., Fraundorfer, M. R. and Kabalin, J. N.: Holmium: YAG laser resection of the prostate (HoLRP) versus transurethral electrocautery resection of the prostate (transurethral prostatic resection): a prospective randomized urodynamicsbased clinical trial. J Urol, suppl., 157: 40, abstract 149, 1997 19. Kabalin, J. N.: Holmium:YAG laser vaporization prostatectomy. J Urol, suppl., 153: 229A, abstract 2, 1995 20. Kabalin, J. N., Mackey, M. J., Cresswell, M. C. et al: Holmium: YAG laser resection of prostate (HoLRP) for patients in urinary retention. J Endourol, suppl., 11: 291, 1996 21. Fraundorfer, M. R., Gilling, P. J. and Kabalin, J. N.: The holmium laser in the treatment of benign prostatic hyperplasia. J Urol, suppl., 155: 318A, abstract 29, 1996
22. Matsuoka, K., Iida, S., Tomiyasu, K. et al: Holmium laser resection of the prostate. J Endourol, 12: 279, 1998 23. Kabalin, J. N., Gilling, P. J. and Fraundorfer, M. R.: Application of the holmium:YAG laser for prostatectomy. J Clin Laser Med Surg, 16: 21, 1998 24. Gilling, P. J., Cass, C. B., Malcolm, A. et al: Holmium laser resection of the prostate versus neodymium:yttriumaluminum-garnet visual laser ablation of the prostate: a randomized prospective comparison of two techniques for laser prostatectomy. Urology, 51: 573, 1998 25. Terris, M. K. and Stamey, T. A.: Determination of prostate volume by transrectal ultrasound. J Urol, 145: 984, 1991 26. Greene, L. F.: Transurethral prostatic resection. In: Transurethral Surgery. Edited by L. F. Greene and J. W. Segura. Philadelphia: W. B. Saunders Co., chapt. 9, pp. 108 –164, 1979 27. Dunnett, C. W.: A multiple comparisons procedure for comparing several treatments with a control. JASA, 50: 1096, 1955 28. Anson, K. M., Watson, G. M., Shah, T. K. et al: Laser prostatectomy: our initial experience of a technique in evolution. J Endourol, 7: 333, 1993 29. Gilling, P. J., Kennett, K., Fraundorfer, M. R. et al: Holmium laser resection of the prostate (HoLRP) versus transurethral resection of the prostate (TURP): follow-up at 1 year. J Urol, suppl., 159: 249, abstract 955, 1998 30. Fraundorfer, M. R. and Gilling, P. J.: Holmium:YAG laser enucleation of the prostate combined with mechanical morcellation: preliminary results. Eur Urol, 33: 69, 1998