Urinary Obstruction & Benign Prostatic Hyperplasia (BPH),Xiao Huang, MD; PhDDepartment of Urology,1st Affiliated Hospital of Zhejiang University, School of Medicine,Urinary Obstruction,Urinary Tract Anatomy Urinary Obstruction Reason of Urinary Obstruction Hydronephrosis,Urinary Tract Anatomy,Urinary Obstruction,Reason of Urinary Obstruction,Obstruction Reason Classification,Dynamic and structural Congenital and aquired Populations Child: congenital Adults: stone, injury, tumor ,TB Women: pelvic disease Old men: BPH Locations Kidney: calculus, tumor, infection, TB, UPJ stricture, congenital deformity Ureter: stone, tumor, iatrogenic injury, ureteritis,TB , Metastatic carcinoma Bladder: BPH, bladder neck contracture, tumor, calculus, Neurogenic bladder Urethral: urethral stricture, Phimosis ,Congenital Posterior urethral valve ,stone.,Hydronephrosis,What is hydronephrosis? Hydronephrosis is a “stretching“ or dilation of the inside, or collecting part, of the kidney. It often results from a blockage in the ureter where it joins the kidney that prevents urine from draining into the bladder. Urine is trapped in the kidney and causes it to stretch. Hydronephrosis may also be due to abnormal backwash or “reflux“ of urine into the bladder.,Degrees of Hydronephrosis,Kidney function: Minimally affected compensation damage,Benign Prostatic Hyperplasia (BPH),Objectives,What is a BPHHow to approach a patient with LUTS (lower urinary tract symptoms)Treatment of BPH,Outline,1. Definition of BPH2. Anatomy and Physiology3. Microscopic Appearance 4. Prevalence of BPH5. Etiology6. Natural History of BPH7. LUTS8. Approach to a patient with BPH9. IPSS 10. Differential Diagnosis 11. Management of BPH 12. Treatment of BPH,1.Definition,BPH is a nonmalignant enlargement of the prostate gland caused by cellular hyperplasia of both glandular and stromal elements that leads to troublesome lower urinary tract symptoms (LUTS) in some menIt is the most common benign tumor in men and is not a precancerous condition,2.Anatomy and physiology,The prostate is a compound tubuloalveolar exocrine gland of the male mammalian reproductive systemFunction is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semenSecret is composed of simple sugars and proteins (proteolytic enzymes, acid phosphatase, prostate-specific antigen);zinc and citric acid,Lower urinary tract,2. Anatomy and physiology,A healthy human prostate is slightly larger than a walnut (4cm by 3cm). It surrounds the urethra just below the urinary bladder and can be felt during a rectal exam. It has anterior, median, posterior and two lateral lobesRelations: Posterior: rectal ampulla (Denonvilliers fascia);Superior: bladder neck ; Anterior:pubic symphysis (retropubic space of Retzius); Inferior: urogenital diaphragmIts work is regulated by androgens which are responsible for male sex characteristics,2.Anatomy and physiology,Glandular cells produce milky fluid that liquefies semen Smooth muscle cells, which contract during sex and squeeze the fluid from the glandular cells into the urethra, where it mixes with sperm and other fluids to make semen. The muscle cells are stimulated by alpha adrenergic receptors Stromal cells (which form the structure of the prostate) The prostate gland also contains an enzyme - 5 alpha-reductase that converts testosterone to dihydrotestosterone,2.1. Zonal Anatomy(McNeal-1972),Peripheral Zone 70% of the young adult (60-70% of CaP)Central Zone 25% (5-10% CaP)Transition Zone 5% ( 10-20% CaP) BPH,Zonal Anatomy,3.Microscopic Appearance,Prostate consists of a thin fibrous capsule under which are circulary oriented smooth muscle fibres and collagenous tissue. Prostatic stroma lies deep to this layer and is composed of connective and ellastic tissue and smooth muscle where epithelial cells are embeded As a male ages, there are more likely to be small concretions within the glandular lumina, called corpora amylacea, that represent laminated concretions of prostatic secretions. The glands are normally separated by stroma The thin layer of connective tissue that surrounds the prostate merges with surrounding soft tissues, including nerves,4.Prevalence of BPH,In men 20 to 30 years of age, the prostate weighs about 20 g; however, the mean prostatic weight increases after the age of 50.,4.Prevalence of BPH,20% of men age 41-50 50% of men age 51-60 65% of men age 61-70 80% of men age 71-80 90% of men age 81-90lower urinary tract symptoms associated with BPH increase with age.,Pathophysiology of Clinical BPH: Predictive Risk Factors,Slide I.4,Increasing age Prostatic enlargement Lower-urinary-tract symptoms (LUTS) Decreased urinary flow rate Elevated prostate-specific antigen (PSA),5.Etiology of BPH,Androgens Estrogens Lifestyle Hereditary(genetic)/Race,5.1 Androgens,Testosterone and related hormones play a permissive role in BPH Androgens have to be present for BPH to occurAdministering exogenous testosterone is not associated with a significant increase in the risk of BPH symptoms Didhydrotestosterone (DHT), a metabolite of testosterone is a critical mediator of prostatic growth. DHT is synthesized in the prostate from circulating testosterone by the action of the enzyme 5-reductase, type 2. This enzyme is localized principally in the stromal cells; hence, these cells are the main site for the synthesis of DHT DHT can act in an autocrine fashion on the stromal cells or in paracrine fashion by diffusing into nearby epithelial cells. In both of these cell types, DHT binds to nuclear androgen receptors and signals the transcription of growth factors that are mitogenic to the epithelial and stromal cells. DHT is 10 times more potent than testosterone because it dissociates from the androgen receptor more slowly the active androgen, DHT, is important in promoting growth of prostate that would eventually lead to symptomatic BPH.,