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The principal aim of this chapter is to evaluate the urodynamic and clinical outcomes at 6 months follow-up in men with or without significant IPP ( > 5 mm) undergoing HoLEP for BOO. Eight-four patients underwent HoLEP between January 2018 and December 2021. Inclusion criteria: men aged 50–75 years with prostate size from 30 to 100 grams, peak urinary flow rate less than 15 ml/s, and a diagnosis of BOO. At 6-month follow-up, urodynamics data show a statistically significant reduction in PdetOpen and PdetQmax compared with baseline in both IPP and no IPP groups. Statistically significant differences were found in maximal urodynamic bladder capacity before and after the operations in both groups as also IPSS data, Qmax, Qave, PVR and IPSS total score at 6 months when compared with preoperative data. HoLEP is efficient in improving functional outcomes and obstructive symptoms regardless of the presence of IPP. Surgeons can expect better postoperative outcomes in terms of Qmax, Qave and IPSS total score in patients with significant IPP.
Department of Urology, Fondazione IRCCS Casa Sollievo Della Sofferenza, San Giovanni Rotondo, Italy
*Address all correspondence to: lorenzocapone@msn.com
1. Introduction
Lower urinary tract symptoms (LUTS) have traditionally been related to bladder outlet obstruction (BOO), which is often caused by benign prostatic enlargement (BPE) resulting from the histologic condition of benign prostatic hyperplasia (BPH) [1, 2]. Despite bladder dysfunction may cause LUTS as well as other structural or functional abnormalities of the urinary tract, BPH is the major etiology of LUTS in men older than 50 years: almost more than 70% of patients greater than 70 years old is affected [2, 3].
Recent studies have emphasized the relationship between prostate configuration and BOO associated with LUTS suggesting the idea of a prostate adenoma arising from nodular hyperplasia that distorts the prostatic urethra rather than compressing it [4, 5, 6]. Unlike prostate volume (PV), the intravesical prostatic protrusion (IPP) has been shown that it well correlates with poor urinary flow and the presence of BOO [6, 7]. IPP is a phenomenon in which the prostate adenoma enlarges into the bladder along the plane of least resistance leading to a “ball-valve” type of obstruction, which disrupts the funneling effect of the bladder neck and leads to an uncoordinated movement of the detrusor muscle during voiding [7, 8, 9].
Surgical intervention is the standard treatment for patients with bothersome LUTS due to BOO who are unwilling to try medical therapies, both in cases where medical therapies were not effective and in cases of complicated LUTS [10, 11]. Historically, transurethral resection of the prostate (TURP) has been the gold standard to which all endoscopic procedures for BPH are compared, but, in the past 2 decades, a wide range of innovative transurethral procedures have challenged his supremacy. Holmium laser enucleation of the prostate (HoLEP) proposed by Gilling et al. in 1995 [12] seems to be a valid alternative to standard TURP with comparable functional outcomes, symptoms improvement, a shorter catheterization and hospitalization times [13, 14, 15]. Urodynamic studies and in particular pression/flow studies can provide objective and crucial diagnostic information before and after the treatment, and there is a general agreement that these studies are the basis to quantify BOOs [16, 17].
The principal aim of this study is to evaluate the urodynamic and clinical outcomes at 6 months follow-up in men with or without significant IPP (>5 mm) undergoing HoLEP for BOO.
We enrolled 84 patients who underwent HoLEP at our Institution between January 2018 and January 2021. Inclusion criteria were men aged 50–75 years with prostate size from 30 to 100 g, peak urinary flow rate (Qmax) less than 15 ml/s and a diagnosis of BOO, according to clinical symptoms, and related examinations. Exclusion criteria were patients with urologic tumors, uncontrolled diabetes, neurogenic bladder, previous radiation therapy and patients who refused to agree with the informed consent.
All patients underwent a preoperative examination with anamnesis, digital rectal examination, urinalysis, uroflowmetry (URF), trans abdominal ultrasonography with IPP evaluation, postvoid residual urine volume (PVR), blood analysis with prostate specific antigen (PSA) and a urodynamic study with pression/flow study (UDS). All patients compiled the International Prostate Symptoms Score (IPSS).
Operation indications were medical therapy failure, refusal of medical treatment and a BOO diagnosed by UDS. All patients performed an outpatient visit, URF, UDS, PVR and IPSS after 6 months from the operation.
For the assessment of the IPP most of the studies use transabdominal ultrasound with a bladder capacity between 150 and 250 ml. IPP was defined as the vertical distance from the tip of the intravesical protrusion to the bladder circumference at the base of the prostate gland. With respect to these measurements, the grading system was: Grade I < 5 mm; Grade II 5–10 mm; Grade III > 10 mm. The literature agrees that Grade II and III are correlated to severe BOO, and this has been considered as positive in our study [7, 18].
We divided the patients into two groups based on the IPP: patients with bladders with IPP of 5 or less were assigned to group 1 (no IPP group) and patients with IPP of 6 or more were assigned to group 2 (IPP group).
In order to minimize the bias and for more precise IPP measurement the same urologist performed the transabdominal ultrasound with the same device.
UDS was performed following the recommendation of the International Continence Society, Good Urodynamics Practices and Terms [19] by the same examiner throughout the study period with the same device (SmartDyn, Albyn Medical S.L, Cordovilla, E). The intravesical pressure was measured using a double lumen 6 Ch catheter; the abdominal pressure using a rectal balloon catheter. Cystomanometry was performed with sterile saline solution (0.9%) at 25°C with infusion rate of 50 ml/min. Transducers were balanced at atmospheric zero. The patient was asked to report any sensation relating to bladder filling (first sensation, normal sensation and strong desire to void); the volume at which additional filling was stopped was considered the maximal urodynamic bladder capacity (UBC). During pression/flow study, it was measured the detrusor pressure at urethral opening pressure (Pdet Open) at maximum flow (Pdet Qmax), and it was plotted on two graphics: the Schafer and the ICS nomograms, in order to evaluate the degree of obstruction and the detrusor strength. The UDS was performed before the operation and after a 6-months follow-up.
The surgical technique used for the enucleation of the prostate was the same first described by Gilling et al [12]. The holmium laser energy was delivered by a 550-micron fiber placed in a 24 Ch resectoscope and the same urologist performed enucleation with a high-power holmium laser (100-Watt platform, Lumenis). The settings were 2.0 J energy and 40–50 Hz frequency; hemostasis settings were 1.5 J and 30 Hz with a wide pulse. Once enucleation was completed, the inner laser sheath was replaced with a straight nephroscope and a morcellator was introduced. This was used to extract the prostate tissue once the bladder had been fully distended using dual inflows. After the procedure, a 22 Ch 3-way silicon Dufour was used and catheterization time, hospital stay, and hemoglobin were recorded.
Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS), version 26.0 (SPSS Inc., Chicago, IL). p-Values <0.05 were considered statistically significant. Student t-test was used for the comparison between means of independent groups, and 2-tailed t-test for paired samples. All patients provided written informed consent.
Among 84 patients who underwent HoLEP, 41 were included in group 1 (IPP ≤ 5 mm) and 43 in group 2 (IPP > 5 mm). The mean patients age was 63.3 ± 5.3. In line with Schafer and ICS nomograms all patients were obstructed at baseline (Schafer > 2, “Obstructed” in accordance with ICS). There were statistically significant differences between IPP and no IPP groups in terms of mean serum PSA level and PV (IPP: 2.9 ± 0.5 ng/mL, 68.2 ± 9.0 g; no IPP: 2.0 ± 0.3 ng/mL, 53.9 ± 5.3 g; p < 0.001). There was also a significant difference between the two groups in terms of IPSS total score during the outpatient visit before the operations (IPP: 26.1 ± 1.5; no IPP 23.1 ± 0.8; p < 0.001).
As far as it concerns the operative and post-operative data, the overall operative time was significantly longer in the IPP group (IPP: 81.3 ± 12.4 min; no IPP 72.4 ± 5.4; p < 0.05) and the catheterization time that was slightly lower in no IPP group (IPP: 107.2 h ± 12.2 h; no IPP: 96 ± 7.4 h; p < 0.003). Blood loss and general hospital stay were equivalent in both groups and not statistically significant as the surgical complications (Table 1). After the operation, all patients were dismissed with antibiotic therapy to minimize the irritative symptoms related to the procedure.
Characteristic
IPP
No IPP
p-Value
No. of patients
43
41
/
Age (year)
63.87 ± 5.89
67.77 ± 4.78
/
Total PSA (ng/ml)
2.89 ± 0.55
2.01 ± 0.26
<0.001
Prostate volume (g)
68.20 ± 9.08
53.92 ± 5.31
<0.001
IPSS total score
26.06 ± 1.58
21.23 ± 5.89
<0.001
Total operative time (min)
81.33 ± 12.46
72.38 ± 5.47
0.24
Hemoglobin (g/dl)
Preoperative
14.94 ± 0.69
14.23 ± 0.72
0.14
Postoperative
13.96 ± 0.70
13.39 ± 0.68
0.20
Hospital stay (hour)
76.80 ± 9.93
73.22 ± 5.08
0.09
Catheterization time (hour)
107.28 h ± 12.38
96.48 ± 7.41
<0.003
Table 1.
Patient characteristics and perioperative outcomes.
At 6 months follow up, urodynamics data show a statistically significant reduction in PdetOpen and PdetQmax compared with baseline in both IPP and no IPP groups (IPP: PdetOpen preop 89.8 ± 16 cmH2O, 6-mo 34.5 ± 6.9 cmH2O; no IPP: PdetOpen preop 64.5 ± 11.8 cmH2O, 6-mo 34.8 ± 5.9 cmH2O. IPP: PdetQmax preop 102.5 ± 17.6 cmH2O, 6-mo 36.6 ± 7.1 cmH2O; no IPP: PdetQmax preop 77.5 ± 12.6 cmH2O, 6-mo 38.8 ± 5.2 cmH2O; p < 0.001). Also, the Schafer and ICS nomograms confirm the effectiveness of HoLEP in improving functional outcomes in both all IPP and no IPP patients (Schafer < 2, “Non obstructed” in accordance with ICS). Statistically significant differences were found in maximal UBC before and after the operations in both groups (IPP postop + 38.1 ± 19.2: no IPP post + 18.7 ± 9.4) as also IPSS data, Qmax, Qave, PVR and IPSS total score at 6-months when compared with preoperative data (Table 2, p < 0.001).
Pdet Qmax (cmH2O)
IPP
No IPP
p-Value
Baseline
102.53 ± 17.61
77.46 ± 12.62
<0.001
6-Month
36.60 ± 7.16
38.85 ± 5.25
0.39
p-Value
<0.001
<0.001
Pdet open (cmH2O)
IPP
No IPP
p-Value
Baseline
89.8 ± 16.03
64.46 ± 11.81
<0.001
6-Month
34.53 ± 6.93
34.77 ± 5.89
0.92
p-Value
<0.001
<0.001
UBC (ml)
IPP
No IPP
p-Value
Baseline
89.8 ± 16.03
64.46 ± 11.81
<0.001
6-Month
34.53 ± 6.93
34.77 ± 5.89
0.045
p-Value
<0.001
<0.001
Schafer (points)
IPP
No IPP
p-Value
Baseline
4.67 ± 0.81
4.46 ± 0.52
0.24
6-Month
1.30 ± 0.73
1.55 ± 0.37
0.53
p-Value
<0.001
<0.001
Qmax (ml/s)
IPP
No IPP
p-Value
Baseline
7.66 ± 1.99
8.67 ± 2.46
<0.001
6-Month
23.88 ± 2.36
21.11 ± 1.01
<0.001
p-Value
<0.001
<0.001
Qave (ml/s)
IPP
No IPP
p-Value
Baseline
2.98 ± 0.92
4.01 ± 1.21
<0.001
6-Month
12.63 ± 1.62
10.24 ± 1.05
<0.001
p-Value
<0.001
<0.001
PVR (ml)
IPP
No IPP
p-Value
Baseline
75.33 ± 22.24
70.77 ± 11.15
<0.51
6-Month
38.73 ± 15.94
46.38 ± 8.61
<0.13
p-Value
<0.001
<0.001
IPSS (points)
IPP
No IPP
p-Value
Baseline
26.07 ± 1.58
21.23 ± 5.89
< 0.001
6-Month
3.67 ± 0.81
5.92 ± 0.95
< 0.001
p-Value
<0.001
<0.001
Table 2.
Urodynamic test outcomes at baseline pre-Holep and 6 months after surgery in patient with significant or nonsignificant IPP.
A comparison was also made between IPP and no IPP group patients before and after surgery with statistically significant differences. IPP group had a higher IPSS total score, PdetOpen and PdetQmax at baseline (IPP vs. no IPP: PdetOpen 89.8 ± 16.0 vs. 64.5 ± 11.8 cmH2O; PdetQmax 102.5 ± 17.6 vs. 77.5 ± 12.6 cmH2O, p < 0.001; IPSS score 26.1 ± 1.6 vs. 21.2 ± 5.9, p < 0.05) associated with a lower maximal UBC (IPP vs. no IPP: 316.6 ± 35.1 vs. 371.3 ± 45.6 ml; p < 0.01). Furthermore, the IPP group was associated with a higher postoperative Qave, Qmax (IPP vs. no IPP: Qave 12.6 ± 1.6 vs. 10.6 ± 1.1 ml/s; Qmax 23.9 ± 2.4 vs. 21.1 ± 1.0 ml/s; p < 0.001) and a lower IPSS total score than the no IPP group (IPP vs. no IPP: IPSS score 3.7 ± 0.8 vs. 5.9 ± 0.9, p < 0.001). No statistically significant decrease was observed after 6 months in PdetOpen, PdetQmax and UBC values in IPP group compared to no IPP group (Table 3).
Table 3.
Outcomes between IPP and non-IPP group in terms of PdetQmax, PdetOpen, Qmax and Qave.
To the best of our knowledge, this is the first study showing the functional outcomes after HoLEP in men with significant IPP and one of the few reports considering postoperative urodynamic data in patients with severe BOO.
We know that BOO results from functional or anatomic etiologies and produces compression or resistance upon the bladder outflow channel at any location from the bladder neck to the urethral meatus. This produces LUTS, which may be predominantly obstructive, irritative, or often a combination of both [20].
As a result of chronic obstruction, the bladder wall is markedly remodeled, including cellular hyspertrophy, hyperplasia, and reorganization of the structural relationship between connective tissue and smooth muscle elements [21, 22]. All these changes lead to an initial detrusor overactivity (DO), but the longer BOO persists, the more function instability remains, ending with a hypo/acontractile bladder [23].
Urodynamics with pressure flow studies remains the gold standard for diagnosing and quantifying BOO [24] because they provide patients with correct information about their recovery in case of DO or reduce the non-necessary number of medical or surgical interventions in case of hypocontractility. For this reason, a urodynamic study is essential for a correct functional assessment in patients with BOO, irrespective of the procedure [19, 25]. Within this context there are several studies that focused not only on the size of the prostate but also on its shape and in particular on the association between IPP and BOO.
Chia et al. in 2003 were the first who demonstrated a correlation between IPP and BOO. They suggested the IPP obstruction as a “ball-valve” type capable of disrupting the funnel effect of bladder neck and causing a dyskinetic movement of the bladder during voiding. IPP in enrolled patients was graded using transabdominal US in 3 groups: grade I (<5 mm), grade II (5–10 mm), grade III (>10 mm). In patients with BOO confirmed on the pressure-flow study, grade III IPP was associated with a higher BOO index (BOOI) than grade I–II (P < 0.001) [7]. Keqin et al. in 2007 reported an association between reduced Qmax at URF and severe BOO in significant IPP patients (IPP > 10 mm). They also demonstrated the benefit from early surgical intervention in these patients [26]. Rieken et al. in their 2017 systemic review summarized that IPP measured with transabdominal US is a simple and accurate method to predict BOO emphasizing the correlation between an IPP > 10 mm and a reduced Qmax, an increased BOOI and detrusor wall thickness [27].
Other important findings are the strong correlation between high IPP and trial without catheter (TWOC) or medical treatment effect. Mariappan et al. in 2007 [28] studied 121 patients with acute urinary retention related to BPH and receiving alpha-blockers before a TWOC; IPP appears to strongly predict the outcome of a TWOC that was more likely to fail in patients with IPP larger than 10 mm. Another study showed that patients with high grade IPP after an acute urinary retention episode had an unsuccessful TWOC close to 90% [29]. Lee et al. [30] found that patients with IPP grade II–III had a significantly higher risk of clinical progression of BPE after a 32-month follow-up compared to patients with IPP grade I.
Despite the large number of studies correlating high grade IPP with BOO clinical progression, only three studies investigated the presence and degree of IPP with postoperative outcome after BOO surgery.
Lee et al. in 2012 reviewed 177 patients who underwent TURP and followed them after 6-month follow-up. They divided patients into 2 groups—no IPP (<5 mm), IPP (≥5 mm)—and considered IPSS total and partial score (IPSS-voiding; IPSS-storage), QoL, Qmax, PVR and transitional zone volume (TZV). At 6-month follow-up after the surgical procedure IPSS, IPSS-v, IPSS-s and QoL score were better in IPP group, and this concluded that IPP is an independent parameter for predicting postoperative outcomes in BPH patients undergoing TURP [31].
On the other hand, two other studies on patients undergoing photoselective vaporization of the prostate (PVP) with 120 W HPS laser did not find statistically significant differences in outcomes between patients with or without IPP [32]. Kim et al. evaluated the presence of IPP in 134 patients between January 2010 and July 2011 by retroflexed view from flexible cystoscopy (significant IPP > 5 mm). The Qmax was improved in the IPP group (+7.8 ml/L/s) compared with no IPP group (+6.0 ml/s) and in total IPSS, IPSS-v and IPSS-s as well, after 1 and 3 months. The superiority of the IPP group was not sustained at 6-month follow-up [33].
Our study takes into consideration patients subjected to HoLEP that both the EAU and AUA guidelines on the surgical treatment of BPH recommend as a size-independent treatment option for those men with moderate to severe symptoms [11, 34]. In line with the literature, we noticed that patients in the IPP group had a higher serum PSA (+0.88 ng/mL) and IPSS total score (+4.8 points) because of their larger prostatic volume (+14.3 gr). Our study also showed a higher PdetOpen (+25.3 cmH2O) and PdetQmax (+25.1 cmH2O) at baseline in IPP patients associated with a lower UBC (−54.7 ml). This data can be explained by the fact that opening bladder neck and urethral channel during micturition is more difficult and requires a more forceful detrusor contraction when there is a middle lobe protrusion causing constriction [35, 36]. We also noticed a dramatic improvement in urodynamics and clinical findings in both groups of patients before the procedure and at 6-month follow up. In particular, pression/flow studies showed that an early diagnosis of BOO due to prostatic obstruction is associated with excellent surgical outcomes regardless the presence of IPP and with a normal detrusor motor activity; most likely because the detrusor did not still have irreversible damage (IPP group Qmax + 16.2 mL/s; PdetQmax – 65.9 cmH2O; PVR – 35.6 mL; UBC + 38.1 ml. No IPP group Qmax + 12.4 mL/s; PdetQmax – 38.6 cmH2O; PVR – 24.4 ml; UBC + 18.7 ml. p < 0.001) (Figures 1 and 2).
Figure 1.
Urodynamics showing BOO pre-Holep.
Figure 2.
Normal urodynamics post-Holep.
As regards the functional and clinical outcomes between the two groups at 6-month follow-up, we noticed an increased Qmax (+2.77 ml/s) and Qave (+2.39 ml/s) in the IPP group, but these data were not endorsed by the UDS counterpart that showed non-statistically differences between the two groups. Similar data were published in 2006 by Rigatti et al. [37] who compared urodynamic studies in patients undergoing TURP and HoLEP before and after 1-year follow-up and found PdetQmax value not particularly efficient in describing an effect of surgery on BOO. Lastly, patients with significant IPP experienced less symptoms at 6-month follow-up IPSS total score (−2.26 points) in agreement with Lee and his group [31].
A limitation of this study is the lack of information at a greater distance (1 year), also considering the long-term complications of the procedure like incontinence, urethral stricture, or erectile dysfunction.
Our results demonstrated that HoLEP is efficient in improving functional outcomes and obstructive symptoms regardless the presence of IPP. We also show that surgeons can expect better postoperative outcomes in terms of Qmax, Qave and IPSS total score in patients with significant IPP; this likely because a higher detrusor activity without bladder wall irreversible damage had been urodinamically detected.
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Written By
Lorenzo Capone
Submitted: 12 July 2022Reviewed: 30 September 2022Published: 10 November 2022
Open access peer-reviewed chapter
