Results
Among 1608 patients, bladder compliance was < 12.5 mL/cm
H2O in 50 patients (3.1%), and 12.5-25 mL/cm
H2O in 232 patients (14.4%) (Table 1). Bladder
compliance decreased as age increased (72.9 vs. 68.9 vs. 68.4 years,
p<0.001) and body mass index decreased (22.9 vs. 23.6 vs. 24.1
kg/m2, p=0.002). The I-PSS total score (22.3 vs. 19.5
vs 19.0, p=0.018), storage sub-score (9.0 vs. 8.2 vs. 7.5, p=0.002), and
quality of life (QoL) index (4.7 vs. 4.2 vs 4.1, p=0.001) increased as
bladder compliance decreased, although the voiding sub-score was
equivalent regardless of bladder compliance. PVP was more frequently
performed in patients with decreased bladder compliance compared to
HoLEP. At postoperative 6 months, the percent decrease in PSA (p=0.854)
and prostate volume (p=0.755) were similar regardless of bladder
compliance (supplementary table
1).
At postoperative 1, 12, and 36 months, I-PSS total, storage sub-score,
and QoL index, respectively, were equivalent according to bladder
compliance, although the preoperative values were significantly
different (Supplementary table 2). In addition, the peak flow rate also
showed no difference at postoperative 1, 12, and 36 months according to
bladder compliance. However, BVE was significantly higher in men with
bladder compliance >25 mL/cmH2O than
decreased bladder compliance at postoperative 36 months, although there
was no difference in BVE at postoperative 1 and 12 months. The 5-year
serial follow-up data was demonstrated in Supplementary table 3.
Decreases in I-PSS total score were significantly higher in patients
with bladder compliance < 12.5 mL/cm H2O at
postoperative 36 months (-14.3 vs. -8.5 vs. -7.4, p=0.019) (Table 2).
Although decreases in voiding sub-score were equivalent regardless of
bladder compliance, decreases in storage sub-score (-5.5 vs. -3.1 vs.
-2.3, p=0.006) and QoL index (-2.8 vs. -2.1 vs. -1.7, p=0.031) at
postoperative 36 months were significantly higher in patients with
bladder compliance < 12.5 mL/cm H2O than in
the other groups. However, there was no difference in total I-PSS score,
voiding sub-score, and storage sub-score decreases according to bladder
compliance at postoperative 1 and 12 months. Changes in the objective
parameters, including peak flow rate and BVE, were equivalent during the
postoperative follow-up duration of 36 months, except for the changes in
BVE at postoperative 1 month.
On the multivariable analysis,
bladder compliance < 12.5 mL/cmH2O (B=4.201,
p=0.042), in addition to prostate volume, preoperative I-PSS total
score, and surgical methods, was significantly associated with decreases
in total I-PSS score at postoperative 36 months (Table 3). However,
bladder compliance was not significantly associated with changes in
voiding sub-score although bladder compliance < 12.5
mL/cmH2O (B=2.040, p=0.017) was significantly associated
with storage sub-score after adjusting other variables. On
additional
analysis, bladder compliance,
regardless of the surgical methods, was associated with decreases in
storage score, although statistical significance was not achieved in
patients who underwent HoLEP (Table 4)
On the repeat measured ANOVA analysis, patients with bladder compliance
< 12.5 mL/cmH2O showed significantly superior
improvements in I-PSS storage score (vs. >25
mL/cmH2O; difference: -1.4, p=0.002, vs. 12.5-25
mL/cmH2O; difference: -1.3, p=0.023) and total score
(vs. >25 mL/cmH2O; difference: -4.2,
p=0.027, vs. 12.5-25 mL/cmH2O; difference: -4.9,
p=0.026) compared to the other groups, although I-PSS voiding score was
equivalent regardless of bladder compliance (Supplementary table 4).