Influence of prostatic prolapse into bladder (IPP) on postoperative positive margins and continence recovery

Introduction Robot-assisted laparoscopy and laparoscopic radical prostatectomy (LRP) are important methods for the treatment of localized and locally advanced prostate cancer
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Intravesical Protrusion of Prostate (IPP) is a difficult situation in LRP surgery, which may affect multiple surgical steps: First, the prostatic gland protruding into the bladder will affect the operator's judgment of the boundary of the bladder neck and the ureter.
important anatomical landmarks such as the mouth; secondly, the blocking of the glands protruding into the bladder will make it difficult to cut off the posterior wall of the bladder, which will affect the operator to find the vas deferens and seminal vesicles; in addition, the prostatic bladder neck protruding into the bladder glands and the huge mouth are generally larger , the anastomotic tension is large, and most patients need bladder neck reconstruction
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The results of previous clinical studies suggest that IPP is associated with prolonged operation time, increased blood loss, and increased perioperative complication rate.
In addition, IPP may have a negative impact on the recovery of urinary continence after LRP
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Figure 1 MRI findings of prostate protruding into the bladderFigure 2 IPPL: coronal measurement of the vertical distance from the apex of the prostatic tissue protruding into the bladder to the base of the bladder.
Analysis of the effect of IPP on postoperative urinary continence in patients with prostate cancer Our previous retrospective study[1] The results suggest that IPPL (see Figure 2) is of great significance for the recovery of early urinary continence after prostate cancer surgery.
For patients with prostate cancer whose prostate protrudes into the bladder, patients and their families should be fully explained to the patients and their families before surgery.
Risk of delayed recovery
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The main reasons for delayed recovery of urinary continence caused by IPPL include: 1.
It is difficult to retain the bladder neck for those who have obvious prolapse of the prostate into the bladder, and the damage to the internal urethral sphincter is relatively large, which affects the patient's ability to maintain sufficient intraurethral pressure after LRP; 2.
Among the patients with large prostate gland and prostatitis protruding into the bladder, the proportion of patients with bladder outlet obstruction and bladder dysfunction is significantly higher.
Such patients may have overactive bladder before surgery, and postoperative bladder instability and bladder dysfunction.
Involuntary contraction will cause abnormal increase of intravesical pressure, which will lead to urinary incontinence; 3.
IPPL is significantly related to prostate volume (PV).
The huge volume of the prostate will lead to a narrow operation space, which is not conducive to the preservation of neurovascular bundles and functional preservation during the operation.
Both urethral length will have an impact, and neurovascular bundle damage and functional urethral length defect are also important factors that cause delayed recovery of urinary continence in patients after surgery
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In our study [1], the patients were divided into two groups according to different IPPLs (group B1: the prostate did not protrude into the bladder obviously, IPPL<5mm; group B2: the prostate protruded into the bladder obviously, IPPL≥5mm).
The effect of continence recovery
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Fig.
3 KM curve of urinary continence recovery after different IPPL and RP In addition, Table 1 analyzes the factors that may affect the recovery of urinary continence after prostate cancer surgery
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Table 1 Univariate and multivariate analysis of urinary incontinence recovery after laparoscopic radical prostatectomy The effect of IPP on postoperative positive margins in prostate cancer patients Analysis of positive margins (PSM) may occur in the apex, base, Bilateral lobes, posterior and anterior parts, with the highest incidence rate at the apex of the prostate; positive basal incisal margin (PBSM) occurs at the dissection surface of the prostate and bladder, which is related to the step of dissecting the bladder neck during LRP, and IPP will increase The operational difficulty of this surgical step
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One of our retrospective studies [2] explored the correlation of IPPL with PSM and PBSM after LRP, and the results showed that IPPL measured by preoperative MRI was an independent risk factor for PBSM, but not for PSM
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The results of the study suggest that, for patients with prostate cancer with obvious protrusion of the prostate into the bladder, especially those with locally advanced (cT≥T3) prostate cancer, patients and their families should be fully explained to the patients and their families about the risk of positive postoperative basal margins before surgery.
Adjuvant therapy such as adjuvant external radiotherapy
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We consider the possible reasons why IPP affects the increased incidence of PBSM: 1.
Influenced by the glands protruding into the bladder, the position of the bladder neck is unclear during surgery; 2.
There is tissue adhesion between the mucosa of the bladder neck and the glands; 3.
Due to the occlusion of the glands, the posterior wall of the bladder neck cannot be exposed, resulting in the incision of the prostate tissue during the operation; 4.
Overemphasis on preserving the bladder neck mucosa and small neck opening results in residual glands and tumors
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Tables 2 and 3 analyze the possible causes of PSM and PBSM after laparoscopic radical prostatectomy
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Table 2 Multivariate Logistic regression analysis of independent risk factors for postoperative PSMTable 3 Multivariate Logistic regression analysis of independent risk factors for postoperative PBSM When laparoscopic radical prostatectomy is performed in patients with prostate cancer with obvious bladder protrusion, we recommend: 1.
Carefully read the MRI film before the operation, and predict the degree of protrusion of the middle lobe into the bladder, the side, the relationship with the bladder neck, and the position of the ureteral canal; 2.
During the operation, accurately find the junction of the prostate and the bladder to open the bladder neck, If the observation is unclear, the bladder opening should be appropriately enlarged to avoid overemphasizing the preservation of the bladder neck and causing a positive incision margin; 3.
For patients with obvious protrusion of the middle lobe of the prostate into the bladder, care should be taken to protect the bilateral ureteral orifices, and intravenous furosemide can be administered in advance to assist in the operation Judgment, if necessary, indwelling ureteral stent before operation; when the posterior wall of the bladder neck is severed, the middle lobe of the prostate can be suspended from the abdominal wall to increase the operating space; if the bladder neck opening is too large after prostatectomy, the bladder neck opening should be reconstructed.
The bladder neck can be suspended to improve urethral tension
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Expert Profile Zhang Fan, Doctor of Urology, Peking University Third Hospital, Deputy Chief Physician, Youth Member, Urology and Male Reproductive System Professional Committee, China Anti-Cancer Association Excellent young physicians of the Third Hospital of the Third Hospital of Peking University Third Hospital of the Department of Urology, the main research direction: prostate cancer, benign prostatic hyperplasia Correlation of urinary continence recovery after endoscopic radical prostatectomy [J].
Journal of Peking University: Medical Edition, 2018, 50(4): 621-625.
[2] Zhang Fan, Hao Yichang, Yang Bin, Yan Ye, Wang Guoliang, Xiao Chunlei, Zhang Shudong, Huang Yi, Ma Lulin.
Relationship between prostate protrusion into bladder and positive surgical margins after laparoscopic radical prostatectomy[J].
Chinese Journal of Urology,2020,41(9):656-660.
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