benign prostatic hyperplasia ( bph ) is one of the most common diseases in men of middle age and over in korea .
its importance and frequency are rapidly increasing as the result of increases in the elderly population , increases in the accessibility of westernized diets , increases in desires for improvements in quality of life , and other medical , social , and economical changes .
the early treatment chosen most often for bph is pharmacotherapy , but it is not appropriate for some patients .
when the side effects of pharmacotherapy , such as dry mouth and orthostatic hypotension , are severe , patients may choose surgical treatment instead .
also , in cases accompanied by repetitive urinary tract obstruction , infection , bladder stone , renal failure , and gross hematuria , surgery is considered first rather than medical therapy . up to now , transurethral resection of the prostate ( turp ) was the standard surgical method , but turp can have complications such as postoperative bleeding , urethral stricture , urinary incontinence , retrograde ejaculation , and transurethral resection ( tur ) syndrome . .
photoselective vaporization of the prostate ( pvp ) by use of a laser was attempted as a minimally invasive treatment in order to reduce these side effects .
recently , pvp using an 80 w potassium - titanyl - phosphate ( ktp ) laser or 120 w lithium triborate ( lbo ) laser , which produces high energy , has been introduced and used . according to several studies ,
pvp was also reported to significantly reduce operation time , hospitalization period , and urethral foley catheter indwelling duration and to reduce complications by reducing the amount of bleeding [ 5 - 7 ] .
in particular , the operation time becomes longer and complication rates increase after the operation compared with turp if the prostate size is large .
still , because most previous studies dealt with patients with large prostates and analyzed the surgery results by comparison with turp , it is not clear whether pvp results differ depending on prostate volume [ 6,8,10 - 13 ] .
therefore , in the present study , we divided patients who underwent pvp at our hospital into 2 groups : those with prostate volumes of less than 60 cc and those with volumes of 60 cc or greater .
the two groups were compared in order to examine the utility and stability of pvp depending on prostate volume .
a total of 249 patients with a chief complaint of lower urinary tract obstruction due to bph and who underwent pvp with an 80 w ktp laser or a 120 w lbo laser at two general hospitals from january 2006 to june 2008 were chosen as the subjects for this retrospective study . for comparison and analysis ,
the subjects were divided into group a , with prostate volumes of less than 60 cc , and group b , with prostate volumes of 60 cc or more , on the basis of transrectal ultrasonography performed before surgery .
all patients underwent history taking , physical examination , transrectal ultrasonography , and a blood test for prostate - specific antigen ( psa ) before surgery .
patients with palpable nodes on the digital rectal exam or with psa levels over 4 ng / ml before surgery underwent prostate tissue biopsy to confirm the existence of prostate cancer .
patients showing a neurogenic bladder in the urodynamic studies or those with urinary tract infection or urethral stricture were also excluded .
indications for surgery were an international prostate symptom score ( ipss ) of 12 points or more before surgery and a maximal urinary flow rate ( qmax ) lower than 15 ml / s , acute urinary tract obstruction , hydronephrosis or uremia , repetitive urinary tract infection due to excessive residual urine , bladder stone , and severe hematuria .
questionnaires to assess ipss and quality of life ( qol ) score and tests for examining qmax and postvoid residual volume ( pvr ) were completed before surgery and 1 , 3 , 6 , and 12 months after surgery . for the test items
right after surgery , the total amount of energy used ( kj ) and foley catheter maintenance period were compared .
the operation was done with monitored control anesthesia for all patients . under the guide of videoendoscopy , a 22.5 fr continuous flow cystoscope with a 30 lens
was used . an 80 w ktp laser or a 120 w lbo laser with a wave - length of 532 nm
normal saline ( 0.9% ) was used as the irrigating solution . the size and maintenance period of the urethral foley catheter applied after surgery were determined by considering the surgical findings and level of hematuria after surgery .
most patients had 20 fr three - way foley catheters , which were removed in the morning of the next day after surgery .
results for treatment effects were evaluated with ipss , qol score , qmax , and pvr , whereas stability was evaluated through operation time , foley catheter maintenance period after surgery , hospitalization period , urethral stricture , and urinary tract infection .
preoperative and postoperative baseline values of continuous variables were compared by paired t - test .
relationship with complications due to prostate volume was examined by using the chi - square test .
each statistical value was determined to have a significant difference when the p - value was less than 0.05 .
among 249 patients , 186 were designated as group a and 63 as group b. the average age of group a was 67.27.5 years , and that of group b was 69.46.7 years .
average prostate volume was 38.310.8 cc in group a and 78.615.4 cc in group b. the psa level of group a was 2.061.97 ng / ml and that of group b was
5.934.66 ng / ml . the average ipss of patients before surgery was 20.27.3 for group a and 19.18.3 for group b. the average qol score of group a was 4.51.9 and that of group b was 4.21.3 .
the average qmax was 10.25.3 ml / s in group a and 11.16.0 ml / s in group b. the average pvr of group a was 73.392.0 ml and that of group b was 78.487.5 ml .
only prostate volume and psa levels differed significantly between the two groups at baseline ( table 1 ) .
a total of 128 ( 68.8% ) patients among 168 patients of group a and 49 ( 77.8% ) patients among 63 patients of group b underwent pvp with the 80 w ktp laser .
the average operation time was 46.519.1 minutes for group a and 76.029.8 minutes for group b. the total amount of energy used was 12280 kj in group a and 20089 kj in group b. operation time showed a statistically significant difference .
the foley catheter maintenance period after surgery in group a was 24.415.2 hours and that in group b was 24.610.8 hours .
most of the patients removed their foley catheters and were discharged without any other problems 1 day after surgery [ 156 ( 83.9% ) in group a , 59 ( 93.7% ) in group b ] .
foley catheters were reinserted in 20 patients ( 10.8% ) in group a and 3 patients ( 4.7% ) in group b because of postoperative voiding difficulty . a total of 10 patients ( 5.4% ) in group a and 1 patient ( 1.6% ) in group b were discharged with their foley catheter still inserted .
however , there were no statistically significant differences between the two groups in the foley catheter maintenance period , hospitalization period after surgery , or foley catheter reinsertion rate . concerning complications after surgery , in group a
, there were 33 ( 17.8% ) patients with retrograde ejaculation , 9 ( 4.8% ) with urethral strictures , 7 ( 3.8% ) with urinary incontinence , 4 ( 2.2% ) with urinary tract infections , 2 ( 1.1% ) with hematuria , and 2 patients ( 1.1% ) with impotence . in group
b , there were 9 patients ( 14.3% ) with retrograde ejaculation , 3 ( 4.7% ) with urethral strictures , 2 ( 3.2% ) with hematuria , 1 ( 1.6% ) with urinary incontinence , 1 ( 1.6% ) with urinary tract infection , and 1 ( 1.6% ) with impotence .
a total of 57 ( 30.6% ) patients in group a and 17 ( 27.0% ) patients in group b experienced complications .
there were no significant differences between the two groups in the incidences of total complications or in the incidence of each complication ( table 2 ) .
when all subjects were classified by the laser device used , the prostate volumes of both groups were similar ( 54.022.8 cc in the 80 w ktp laser group and 53.932.8 cc in the 120 w lbo laser group ) .
operation time and the amount of energy used were significantly lower in the 120 w lbo laser group .
however , no statistically significant differences were observed in preoperative or postoperative management or in complications after surgery ( table 3 ) .
follow - up was done at 1 , 3 , 6 , and 12 months after surgery of 152 , 133 , 100 , and 63 patients in group a and of 52 , 40 , 36 , and 26 patients in group b , respectively .
the ipss was 20.2 in group a before surgery and it decreased to 13.4 , 10.8 , 10.5 , and 10.7 at 1 , 3 , 6 , and 12 months after surgery , respectively .
the score in group b was 19.1 before surgery , and it decreased to 11.8 , 8.7 , 7.0 , and 7.6 at 1 , 3 , 6 , and 12 months after surgery , respectively . the qol score in group
a was 4.5 before surgery and was reduced to 2.8 , 2.3 , 2.3 , and 2.2 at 1 , 3 , 6 , and 12 months after surgery , respectively . in group
b , the qol score was 4.2 before surgery and was reduced to 2.9 , 2.1 , 1.6 , and 1.7 at 1 , 3 , 6 , and 12 months after surgery , respectively .
the qmax of group a was 10.2 ml / s before surgery and increased to 17.7 , 17.7 , 16.9 , and 15.7 ml / s each at 1 , 3 , 6 , and 12 months after surgery , respectively . in group
b , the qmax was 11.1 ml / s and increased to 18.7 , 16.7 , 15.6 , and 16.0 ml / s at 1 , 3 , 6 , and 12 months after surgery , respectively .
the pvr was 73.3 ml in group a before surgery and decreased to 24.6 , 21.3 , 20.8 , and 21.8 ml at 1 , 3 , 6 , and 12 months after surgery , respectively . in group
b , the pvr was 78.4 ml before surgery and decreased to 34.2 , 37.3 , 40.6 , and 51.0 ml at 1 , 3 , 6 , and 12 months after surgery , respectively .
the pvr seemed to increase significantly compared with preoperative test results until 12 months after surgery in both groups however , the pvr of group a was similar as time went by after surgery whereas that in group b increased as time went by .
in general , both groups showed a statistically significant improvement in most of the objective and subjective indexes related to treatment effects ( fig .
among 249 patients , 186 were designated as group a and 63 as group b. the average age of group a was 67.27.5 years , and that of group b was 69.46.7 years .
average prostate volume was 38.310.8 cc in group a and 78.615.4 cc in group b. the psa level of group a was 2.061.97 ng / ml and that of group b was
5.934.66 ng / ml . the average ipss of patients before surgery was 20.27.3 for group a and 19.18.3 for group b. the average qol score of group a was 4.51.9 and that of group b was 4.21.3 .
the average qmax was 10.25.3 ml / s in group a and 11.16.0 ml / s in group b. the average pvr of group a was 73.392.0 ml and that of group b was 78.487.5 ml .
only prostate volume and psa levels differed significantly between the two groups at baseline ( table 1 ) .
a total of 128 ( 68.8% ) patients among 168 patients of group a and 49 ( 77.8% ) patients among 63 patients of group b underwent pvp with the 80 w ktp laser .
the average operation time was 46.519.1 minutes for group a and 76.029.8 minutes for group b. the total amount of energy used was 12280 kj in group a and 20089 kj in group b. operation time showed a statistically significant difference .
the foley catheter maintenance period after surgery in group a was 24.415.2 hours and that in group b was 24.610.8 hours .
most of the patients removed their foley catheters and were discharged without any other problems 1 day after surgery [ 156 ( 83.9% ) in group a , 59 ( 93.7% ) in group b ] .
foley catheters were reinserted in 20 patients ( 10.8% ) in group a and 3 patients ( 4.7% ) in group b because of postoperative voiding difficulty .
a total of 10 patients ( 5.4% ) in group a and 1 patient ( 1.6% ) in group b were discharged with their foley catheter still inserted .
however , there were no statistically significant differences between the two groups in the foley catheter maintenance period , hospitalization period after surgery , or foley catheter reinsertion rate .
concerning complications after surgery , in group a , there were 33 ( 17.8% ) patients with retrograde ejaculation , 9 ( 4.8% ) with urethral strictures , 7 ( 3.8% ) with urinary incontinence , 4 ( 2.2% ) with urinary tract infections , 2 ( 1.1% ) with hematuria , and 2 patients ( 1.1% ) with impotence . in group
b , there were 9 patients ( 14.3% ) with retrograde ejaculation , 3 ( 4.7% ) with urethral strictures , 2 ( 3.2% ) with hematuria , 1 ( 1.6% ) with urinary incontinence , 1 ( 1.6% ) with urinary tract infection , and 1 ( 1.6% ) with impotence .
a total of 57 ( 30.6% ) patients in group a and 17 ( 27.0% ) patients in group b experienced complications .
there were no significant differences between the two groups in the incidences of total complications or in the incidence of each complication ( table 2 ) .
when all subjects were classified by the laser device used , the prostate volumes of both groups were similar ( 54.022.8 cc in the 80 w ktp laser group and 53.932.8 cc in the 120 w lbo laser group ) . operation time and the amount of energy used
however , no statistically significant differences were observed in preoperative or postoperative management or in complications after surgery ( table 3 ) .
follow - up was done at 1 , 3 , 6 , and 12 months after surgery of 152 , 133 , 100 , and 63 patients in group a and of 52 , 40 , 36 , and 26 patients in group b , respectively .
the ipss was 20.2 in group a before surgery and it decreased to 13.4 , 10.8 , 10.5 , and 10.7 at 1 , 3 , 6 , and 12 months after surgery , respectively .
the score in group b was 19.1 before surgery , and it decreased to 11.8 , 8.7 , 7.0 , and 7.6 at 1 , 3 , 6 , and 12 months after surgery , respectively .
the qol score in group a was 4.5 before surgery and was reduced to 2.8 , 2.3 , 2.3 , and 2.2 at 1 , 3 , 6 , and 12 months after surgery , respectively . in group
b , the qol score was 4.2 before surgery and was reduced to 2.9 , 2.1 , 1.6 , and 1.7 at 1 , 3 , 6 , and 12 months after surgery , respectively .
the qmax of group a was 10.2 ml / s before surgery and increased to 17.7 , 17.7 , 16.9 , and 15.7 ml / s each at 1 , 3 , 6 , and 12 months after surgery , respectively . in group
b , the qmax was 11.1 ml / s and increased to 18.7 , 16.7 , 15.6 , and 16.0 ml / s at 1 , 3 , 6 , and 12 months after surgery , respectively .
the pvr was 73.3 ml in group a before surgery and decreased to 24.6 , 21.3 , 20.8 , and 21.8 ml at 1 , 3 , 6 , and 12 months after surgery , respectively . in group
b , the pvr was 78.4 ml before surgery and decreased to 34.2 , 37.3 , 40.6 , and 51.0 ml at 1 , 3 , 6 , and 12 months after surgery , respectively .
the pvr seemed to increase significantly compared with preoperative test results until 12 months after surgery in both groups however , the pvr of group a was similar as time went by after surgery whereas that in group b increased as time went by .
in general , both groups showed a statistically significant improvement in most of the objective and subjective indexes related to treatment effects ( fig .
however , turp is associated with a risk of bleeding during surgery and complications such as tur syndrome .
the procedure requires a few days of foley catheter insertion and hospitalization even after surgery .
other complications such as hematuria , urinary tract obstruction , retrograde ejaculation , urethral stricture , and urinary incontinence may occur .
therefore , interest has recently arisen in nonsurgical therapy and minimally invasive treatment . among these
, endoscopic treatment using a laser is known to have treatment effects similar to those of turp but with fewer side effects .
the ktp and lbo lasers that are being commonly used at present all correspond to the green optical spectrum of 532 nm .
they are not easily absorbed in water but are very soluble in hemoglobin . because they are absorbed in the red blood cells in tissues with abundant blood vessels such as the prostate
, they show excellent tissue removal and hemostatic effects through evaporation . owing to these characteristics ,
it also secures a better endoscopic view , less hematuria occurs after surgery , and the foley catheter maintenance period can be minimized .
reports continuously announce that the treatment effects of pvp are the same as after turp [ 5 - 7 ] .
horasanli et al conducted a prospective randomized comparison study of pvp and turp among 76 patients with prostate volumes over 70 cc .
the group that received pvp showed a shorter period of foley catheter maintenance and shorter hospitalization period than did the turp group .
however , operation time was longer and the patients showed less improvement in ipss , qmax , or pvr . also , 7 patients ( 17.9% ) among those who received pvp had to undergo surgery again .
thus , horasanli et al reported than turp was better than pvp in cases of large prostates .
sandhu et al , by contrast , conducted a 1-year follow - up study of 64 patients with prostate volumes of more than 60 cc who received pvp . at 1 year after surgery
, qmax increased from an average of 7.9 ml / s to 18.9 ml / s , pvr changed from 189 ml to 109 ml , and ipss decreased from 18.4 to 6.7 .
in korea , hwang et al reported treatment effects and complications of pvp depending on prostate volumes . according to their study
, there were no improvements in ipss or qol scores for prostates of 60 cc or more .
the foley catheter maintenance period was longer and urinary frequency and urgency occurred more . therefore , hwang et al were opposed to enforcing pvp in patients with large prostates .
meanwhile , choo et al conducted a 2-year follow - up study after pvp in 104 patients .
when analyzing the results by a prostate volume cutoff of 60 cc , 86 patients with volumes less than 60 cc showed an increase of qmax from an average of 8.3 ml / s to 14.2 ml / s at 2 years after surgery .
their pvr decreased from 72.3 ml to 45.8 ml , ipss from 22.6 to 9.9 , and qol scores from 4.4 to 2.3 .
eighteen patients with prostate volumes of 60 cc or more showed an increase of qmax from an average of 8.3 ml / s to 15.5 ml / s , a decrease in the pvr from 128.4 ml to 71.9 ml , a decrease in ipss from 21.5 to 9.7 , and a decrease in qol scores from 4.3 to 2.6 at 2 years after surgery .
our study also compared clinical indexes of ipss , qol score , qmax , and pvr among patients with prostate volumes of less than 60 cc or 60 cc or more .
all of these indexes showed statistically meaningful improvement like that in cases with prostate volumes less than 60 cc .
we thus confirmed that pvp is an effective treatment for those with large prostates . among the clinical indexes , pvr showed a statistically significant increase in both groups a and b when preoperative values were compared with values 12 months after surgery .
however , the pvr in group a was similar after surgery , whereas that in group b increased as time went by .
even so , it is difficult to determine whether this was a general propensity depending on prostate size because other urination indexes did not differ significantly by time .
sandhu et al also confirmed that pvr increased at 12 months after surgery , but statistical significance was not mentioned .
more studies may be required to additionally analyze the relation of pvr with prostate volume . in this study
, we observed a statistically significant difference in average operation time and the amount of energy used depending on prostate size .
however , no statistically significant differences were seen in the foley catheter maintenance period , hospitalization period , or foley catheter reinsertion between the two groups .
this is the same result that lee et al reported from a study of pvp results in 38 patients with prostate volumes of 40 cc or more .
because 0.3 - 0.5 cc of prostate is evaporated per minute by pvp , the operation time and energy increased with prostate volume . meanwhile , bleeding did not increase in larger prostates owing to the excellent hemostatic effects of the ktp laser .
hematuria and urinary tract obstruction did not occur , so prostate volume was not considered to have a significant effect on the foley catheter maintenance period , hospitalization period after surgery , or foley catheter reinsertion .
as for complications after surgery , retrograde ejaculation and urinary stricture occurred the most but there were no statistically significant differences depending on prostate size .
this may be because retrograde ejaculation can not be evaluated objectively and is recognized only when a doctor asks at the outpatient clinic or when the patient complains about his symptoms .
nine ( 4.8% ) patients in the group with prostate volumes less than 60 cc and 3 patients ( 4.7% ) in the group with prostate volumes of 60 cc or more had urethral stricture .
all patients underwent endoscopic internal urethrotomy and are receiving follow - up at the outpatient clinic without any other problems .
the incidence of urethral stricture after pvp is also reported differently in different studies [ 5 - 13,15 ] . this study is not any different from previous studies .
however , whereas hwang et al reported a high incidence of urethral strictures in patients with large prostates , it appeared that prostate volume did not affect the incidence of urethral strictures in our study .
long - term , large - scale analysis and research may be required on this subject in the future . in the present study , we analyzed patients who underwent pvp with an 80 w ktp laser or a 120 w lbo laser .
the surgical devices and methods used were almost identical , and there were no differences in preoperative or postoperative management
. it may be difficult to understand why some items , including operation time , were completely the same because the output energy differed .
however , we conclude that the final treatment results were identical because pvp with both lasers was carried out until an appropriate cavity was formed , like turp , and analysis of stability and usefulness could be done as well .
the supply of 120 w lbo lasers is increasing , so studies of only patients who received pvp with a 120 w lbo laser will become possible . up until now , turp was the gold standard for prostatic hypertrophy .
if long - term follow - up results with various clinical data are sufficiently gathered instead of short - term results on pvp [ 16 - 18 ] , we will be able to better evaluate the advantages and disadvantages of pvp compared with turp .
this study confirmed that pvp significantly improved both objective and subjective urination symptoms , even in patients with prostate volumes of 60 cc or more .
also , there were no statistically significant differences in hospitalization period , foley catheter maintenance period , or complications after surgery compared with those in patients with volumes less than 60 cc .
more research on continuance of treatment effects and incidence of complications through long - term follow - up is required .
 purposethis study was conducted to perform a comparative analysis of the efficacy and safety of photoselective vaporization of the prostate ( pvp ) for treatment of benign prostatic hyperplasia ( bph ) in men with a prostate volume greater than 60 cc.materials and methodsthe clinical data of 249 men with symptomatic bph who underwent pvp between january 2006 and june 2008 were retrospectively analyzed . 
 all patients were classified into two groups according to their prostate volume ( group a , < 60 cc ; group b , 60 cc ) . 
 the preoperative evaluation included a digital rectal exam , urinalysis , prostate - specific antigen levels , international prostate symptom score ( ipss ) , quality of life ( qol ) score , maximal flow rate ( qmax ) , postvoid residual urine volume ( pvr ) , and transrectal ultrasonography . 
 the total operative time , used energy ( kj ) , urethral foley catheter indwelling period , and the number of hospital days were recorded afterward . 
 the ipss , qol score , qmax , and pvr were evaluated at 1 , 3 , 6 , and 12 months postoperatively.resultsin both groups , significant improvements in the subjective and objective voiding parameters were achieved and these improvements were sustainable for at least 1 year with minimal complications . during the follow - up period , 
 the pvr in group b significantly increased . 
 retrograde ejaculation and urethral stricture were the common complications in both groups . 
 there was no significant difference in the incidence rate.conclusionspvp is safe and efficacious , with durable results for men with symptomatic bph and large prostate volumes . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
1. Comparison of patients at baseline
2. Evaluation of treatment safety
3. Comparison of treatment effects
DISCUSSION
CONCLUSIONS