[Expression of TGF-β in bladder neck contracture after transurethral enucleation and resection of the prostate]

To explore the role of transforming growth factor-β (TGF-β) in bladder neck contracture (BNC) after transurethral enucleation and resection of the prostate (TUERP).

This study included 300 BPH patients undergoing TUERP, aged 51－89 (69.19 ± 8.43) years, with the prostate volume of 14.4－355.8 (63.18 ± 47.63) ml and preoperative IPSS of 15－35 (26.07 ± 5.9), QOL score of 3－6 (4.43 ± 0.67), PSA content of 0.17－23.16 (2.94 ± 3.77) ug/L, urinary leukocyte increase in 50 cases, post-void residual urine volume (PVR) of 0－440 (83.53 ± 86.85) ml, and maximum urinary flow rate (Qmax) of 2.3－14.5 (7.77 ± 3.47) ml/s. During TUERP, we collected the tissues from the bladder neck at 5 and 7 o'clock as well as the BPH tissue and the tissue from the residual prostate for HE staining, immunohistochemistry (the SP method) and examination of the infiltration degree of inflammatory cells and expressions of TGF-β1 and TGF-β3. During the 6－24 months follow-up, 6 of the patients were confirmed with BNC based on the clinical symptoms and the results of uroflowmetry and cystoscopy, and underwent transurethral bladder neck incision and detection of the expressions of TGF-β1 and TGF-β3 in the bladder neck tissue with BNC.

The bladder neck tissue without BNC was mainly composed of smooth muscle and fibrous tissues with local infiltration of inflammatory cells, and the residual prostate tissue primarily comprised fibrous and muscle tissues, mixed with a little prostatic epithelial tissue. The bladder neck tissue with BNC, compared with that harvested during the initial TUERP, exhibited significantly increased expression of TGF-β1 (［68.20 ± 10.88］% vs ［36.14 ± 7.62］%, P < 0.05), decreased expression of TGF-β3 (［8.55 ± 4.73］% vs ［20.77 ± 8.69］%, P < 0.05), and enhanced infiltration of inflammatory cells (P < 0.05). The bladder neck tissue without BNC, in comparison with the BPH tissue, showed dramatically up-regulated expressions of TGF-β1 (［27.05 ± 8.21］% vs ［1.61 ± 0.69］%, P < 0.001) and TGF-β3 (［14.09 ± 4.19］% vs ［0.32 ± 0.11］%, P < 0.001) and increased infiltration of inflammatory cells (P < 0.05).

After TUERP, the expression of TGF-β1 is increased, that of TGF-β3 decreased and the infiltration of inflammatory cells enhanced in the bladder neck tissue with BNC, which suggests that BNC may be related to the expression of TGF-β and that BNC after TUERP could be prevented by regulating the expression of TGF-β.