Evaluation for Madigan's prostatectomy in patients with benign prostatic hyperplasia

Li-Min LIAO¹, Bing-Yi SHI¹, Chun-Quan LIANG¹, Werner SCHÄFER²

¹Department of Urology, Beijing Sanlingjiu Hospital, Beijing 100091, China
²Urologische Klinik der RWTH Aachen, Aachen, Germany

Asian J Androl  2001 Mar; 3: 33-37

Keywords: prostatic hyperplasia;  prostatectomy; urodynamics

Abstract

Aim: To comparatively evaluate the efficacy and post-operative complications of the Madigan's prostatectomy (MPC) and suprapubic prostatectomy (SPPC). Methods: A total of 43 patients with benign prostatic hyperplasia were divided into two groups: 21 underwent MPC and 22, SPPC. In all the patients, the international prostate symptom score (IPSS) and urinary pressure-flow studies were assessed before and 6 months after operation. The International Continence Society (ICS) nomogram, Abrams-Griffiths (AG) number and linear passive urethral resistance relation analysis (L-PURR) were used to diagnose and grade bladder outlet obstruction (BOO). The IPSS and the urodynamic parameters before and after operation, as well as the advantages and post-operative complications were recorded and compared. Results: Patients of both the MPC and SPPC groups had a significant improvement in IPSS and urodynamic parameters. Obstruction was relieved in 81.0% of MPC and 86.4% of SPPC patients. MPC has the advantages of the absence of postoperative hematuria and post-catheter stricture, a shorter period of hospitalization, and lower incidence of retrograde ejaculation and erectile dysfunction. Conclusion: Both MPC and SPPC can effectively relieve BOO. MPC has certain advantages and a lower incidence of complications as compared with SPPC.

1 Introduction

Benign prostatic hyperplasia (BPH) is a popular disease in elderly men. In the 1970s, the suprapubic prostatectomy (SPPC) was one of the conventional operative methods for BPH. In 1990, Dixon et al^[1] first reported the employment of Madigan prostatectomy (MPC). In this operation the hypertrophic adenomatous tissue was removed outside the urethra which is thus retained intact. Preservation of urethral intactness gives the method an enormous advantage over the conventional operative procedures. The urine will not leak out from and the blood at the operation site will not leak into the urinary tract. In MPC, postoperative catheter drainage is ordinarily not used or used only for a short period of time as bladder irrigation is not compulsory. Furthermore, preservation of the bladder neck will prevent the occurrence of retrograde ejaculation commonly seen in transurethral resection of prostate (TURP)^[2-4].

2 Materials and methods

2.1 Patients

From 1991 to 1996 a total 43 patients, aged 58-82 (mean 63) years, with BOO resulted from BPH, underwent surgical intervention with either MPC (21 cases) or SPPC (22 cases). All the patients had been subjected to a screening program consisting of digital rectal examination, urine culture, transrectal prostatic ultrasonography, renal ultrasonography, urethrocystoscopy, and the determination of prostate specific antigen and sedimentation rate before surgical intervention; those patients with neurogenic bladder or urethral dysfunction were excluded.

2.2 Surgery and observation

The MPC was performed according to Dixion et al^[1] and SPPC according to the conventional procedure. Before the operation and 6 months after that, subjective (IPSS questionnaire) and objective (urodynamic data) evaluation were accessed. The IPSS questionnaire consists of 7 questions with a maximal score of 5 for each question. The presence of retrograde ejaculation and erectile dysfunction (ED) were also inquired. The urodynamic study, consisting of uroflowmetry, urethral pressure profilometry (UPP), Stress UPP (SUPP), filling cystometry-electromyography and voiding pressure-flow study, was performed using the Dantec Menuet Advanced Urodynamic System. The methods, definitions and units used in the urodynamic study were based on the standards recommended by ICS^[11]. The bladder was catheterized with a 8F catheter with two lumens: one used for medium rate bladder filling with saline at room temperature and the other for pressure recording. The rectum was catheterized with an 8F catheter with a balloon to record the rectal pressure. The pressures in the bladder and rectum and the flow rate were measured with external pressure transducers and flowmeter. The detrusor pressure was calculated by subtraction of the rectal pressure from the intravesical pressure. Throughout the study the pelvic floor electromyography was recorded by self-adhesive electrodes to indicate the behavior of pelvic floor muscles during voiding. Before cystometry with the patient in the supine position, the bladder was emptied through the transurethral catheter and then filled at a speed of 30 mL per minute with sterile saline at room temperature. During the filling phase, the vesical and rectal pressures were examined every minute when asking the patient to cough. At the maximal cystometric capacity (MCC), the patients were asked to stand up to enter the voiding phase. The pressure and flow data were recorded and analyzed by the urodynamic computer program with a flow delay time correction of 0.7 second. Uroflowmetry, UPP and SUPP were done according to the standards recommended by ICS^[11]. The post-voiding residual volume (PVR) was measured by transabdominal ultrasonography. Stress incontinence (SIC) was diagnosed according to the standard of ICS^[11].

BOO was diagnosed and graded according to the different parameters of pressure-flow study that included the maximal flow rate (Q_maxPF), detrusor pressure at the maximal flow rate (P_detQ_max), ICS nomogram^[9], Schaefer nomogram with linear passive urethral resistance relation analysis (L-PURR)^[8,12,13] and AG number (P_detQ_max-2Q_max)^[14]. Different criteria for the diagnosis and grading of BOO consisted of Schaefer L-PURR3, AG number40 and the obstructed area on ICS nomogram.

2.3 Data processing

3 Results

The changes in the urodynamic parameters and IPSS in patients 6 months after treatment are shown in Table 1 and Figure 1. The MPC group had a significant improvement in symptom scores and urodynamic parameters after operation. The IPSS, PVR, and P_detQ_max decreased significantly (P<0.01), the free Q_max and Q_maxPF increased significantly (P<0.01), and both the L-PURR and AG number showed a statistically significant improvement (P<0.01). Table 2 indicated that the incidence of pre-operative BOO was 90.5% with ICS or Scheafer nomogram, while post-operatively only 19.0% of the patients still had BOO and residual obstruction (RO).

As shown in Tables 3 and 4 and Figure 2, the bleeding volume, the duration of catheter drainage, the days of hospitalization as well as the incidences of bladder spasm, hemorrhage, infection, urethral stricture, retrograde ejaculation and ED were significantly lower in the MPC than in the SPPC group (P<0.05 or 0.01). There were no significant differences in prostatic volume and incidence of SIC between the two groups (P>0.05). The incidence of RO and the need of re-operation were higher in the MPC than in the SPPC group (P<0.05).

Table 1. IPSS and urodynamic parameters before and after operation in the 2 groups. ^cP<0.01, compared with the pre-treatment value.

	MPC (n=21)			SPPC (n=22)
	Pre-treatment	6 month post-treatment	Improvement	Pre-treatment	6 month post-treatment	Improvement
IPSS	25.25.1	5.01.5c	20.23.3	26.15.6	3.01.0c	23.13.1
PVR (mL)	113.421.5	14.811.2c	98.615.4	116.557.8	7.58.1c	109.038.1
Qmax(mL/s)	8.50.6	22.81.2c	14.30.8	8.10.5	26.11.2c	18.00.8
MCC (mL)	253.042.0	358.031.2	105.038.0	240.355.0	361.430.2	121.142.3
QmaxPF (mL/s)	8.00.5	21.71.0c	13.70.8	7.50.4	23.60.9c	16.10.7
PdetQmax(cmH2O)	143.98.2	37.86.1c	106.16.1	155.19.2	22.56.1c	132.68.2
L-PURR	5.22.5	1.60.8c	3.21.5	5.52.2	1.20.5c	4.31.3
AG number	127.91.0	-5.71.5c	133.60.9	140.10.8	-24.80.8c	164.90.9

Table 2. Classification and grading of BOO before and after operation in the 2 groups.

	MPC (n=21)				SPPC (n=22)
	Pre-treatment		6 month post-treatment		Pre-treatment		6 month post-treatment
	No.	%	No.	%	No.	%	No.	%
Schaefer nomogram
L-PURRIII	19	90.5	4	19.0	20	90.9	3	13.6
L-PURRIII	2	9.5	17	81.0	2	9.1	19	86.4
ICS nomogram
Obstructed	19	90.5	4	19.0	20	90.9	3	13.6
Equivocal	2	9.5	0	0	2	9.1	0	0
Unobstructed	0	0	17	81.0	0	0	19	86.4

Table 3. Post-operative complications in MPC and SPPC groups.

Table 4.  Comparison of certain clinical indices between MPC and SPPC groups.

Figure 1. The comparison of improvements for symptom scores and bladder outflow obstruction after operation in MPC and SPPC group.
Figure 2. The comparison of incidences of complications between MPC and SPPC groups. 
A: stress incontinence; B: residual obstruction; C: bladder spasm; D: hemorrhage;   E: infection; F: urethral stricture; G: retrograde ejaculation; H: erectile dysfunction; I: re-operation.

4 Discussion

MPC was first reported in 1990 and has been extensively employed in China, but so far in the literature its efficacy and post-operative complication have not been systematically compared with a conventional method. For urodynamic assessment, most previous studies used uroflowmetry, but the reliability of this method alone in the diagnosis of BOO has been questioned. Schaefer et al^[15] reported that only 74% of patients diagnosed as BOO by uroflowmetry were found to be obstructed with pressure-flow study. Furthermore, the differentiation between BOO and detrusor dysfunction, as well as symptom scores can not be determined by means of uroflowmetry^[5,10]. The use of IPSS plus flow rates as the only method of assessment for the effect of prostatism treatment could not give conclusive results in regard to the degree of obstruction and the grading of BOO^[5]. The best method of evaluation is urodynamic assessment, since pressure-flow study is essential in the objective evaluation for the efficacy of treatment aiming at relieving BOO.

In the present study, the post-operative IPSS, PVR, Q_max and pressure-flow parameters were significantly improved in both groups, indicating the effective alleviation of BOO. However, a few cases in both groups still had RO. Currently, the following standards were commonly employed for the determination of post-operative BOO and RO: L-PURRIII, URA29 cm water, Pmuro29 cm water, Athero3.0 mm², and obstructed area on A-G nomogram. ICS nomogram could also be used as a standard. In both groups, all the urodynamic parameters demonstrated a statistically significant improvement after operation. The causes of RO consisted of mid-lobe enlargement, internal and external sphincter spasm, bladder neck fibrosis, retropubic hematoma or abscess, and detrusor bladder neck dyssynergia. Attention should be paid to double obstruction or trapped prostate described by Turner-Warwick^[16], which is a combination of prostatic and dyssynergic bladder neck (DBN) obstruction. In this case, the enlarged prostate is trapped below a tight ring-shaped bladder neck. The obstruction from enlarged prostate can be relieved by MPC, but not from DBN, thus resulting in RO.  MPC should not damage the intactness of bladder neck, so double obstruction is not an absolute indication for MPC and one would rather use SPPC or TURP. In two patients of the present series with double obstruction, TURP were performed after MPC. However, preserving the intactness of bladder neck in MPC will avoid retrograde ejaculation, a  frequently occurring fault in TURP. In MPC, a less operative invasion and the avoidance of retrograde ejaculation result in a lower incidence of ED comparing with SPPC. In MPC, post-operative catheter drainage and bladder irrigation are not needed, thus the common complications of SPPC, such as detrusor instability, incontinence and bladder spasm, are seldom seen. Other advantages of MPC include the absence of post-operative hematuria and clot retention, a decreased requirement for blood transfusion, the avoidance of post-catheter stricture, a lower rate of post-operative urinary infection, etc.

Pre-operative urodynamic assessment will help us to select patients for MPC. Patients with a mid-lobe enlargement, DBN or double obstruction would be better subjected to SPPC or TURP, instead of MPC. Post-operative UPP and SUPP can help to diagnose stress incontinence. There are controversies about whether it is necessary to perform a complete urodynamic evaluation routinely in BPH patients and about the clinical relevance of precisely grading BOO^[10]. We believe that routine urodynamic investigation in BPH is an important practice. In pressure-flow study many procedures have been proposed and it seems that a standardized one is needed to allow clearcut comparison of research results^[17].

5 Conclusion

Urodynamic evaluation shows that MPC can effectively relieve BOO. MPC has certain advantages, including a lower incidence of complications as compared with SPPC.

References

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[16] Turner-Warwick R. A urodynamic review of bladder outlet obstruction in the male and its treatment. In:  Lutzeyer W, Hannappel J, editor. Urodynamics-Upper and lower urinary tract. Berlin: Springer-Verlag; 1985. p 212-40.
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Correspondence to: Dr Li-Min LIAO, Department of Urology, Beijing Sanlingjiu Hospital, Beijing 100091, China.
Tel: +86-10-6677 5133    Fax: +86-10-6287 2826
e-mail: lmliao@public2.east.net.cn
Received 2000-11-27     Accepted 2001-02-12