1.Urinary tract anatomy and relevant pathology Miss Katie Chan CT2 Urology Miss Elizabeth Waine consultant urologist December 2013

2. Overview Embryology Anatomical landmarks Duplex systems PUJ Obstruction Renal Calculi 3. Basic Embryology Day 5/6 after fertilisation 32 cell embryo Implants into endometrium Day 15/16 Embryo has proliferated and 2 cavities form with the intra-embryonic disc between the 2 cavities Cells proliferate on the ectodermal side and form the mesoderm which divides into 3 components Paraxial , intermediate and lateral plate mesoderm. Intermediate mesoderm becomes the genitourinary tract. 4. Embryology of the upper tract Derived from caudal zone of the intermediate mesoderm (IM) either side of the midline Week 4 Early-pronephros appears at the cervical portion of the IM Later-mesonephros forms but degenerates at week 11 Lateral to the mesonephros the mesonephric duct is forming and advances caudally The mesonephric duct canalises and functions briefly to produce urine 5. Embryology of the upper tract Week 5 A ureteric bud forms at the distal end of the mesonephric duct Day 32 ureteric bud fuses with the metanephros and the interaction provides the initiation of the nephrogenesis. Days 28-35 the ureter is patent and fills with mesonephric urine then collapses Week 6-9 The foetal kidneys ascend up the post abdominal wall to adult lumbar position with the unfolding of the foetus Week 6-15 Ureteric bud sequentially branches: renal pelvis, major calyces, minor calyces and collecting ducts 6. Embryology of the lower urinary tract The bladder forms from the anterior portion of the cloaca. The posterior portion forms the rectum Week 4-6 uro-rectal septum descends subdividing the cloaca and is aided by the proliferation and in-growth of the folds of Rathke fully divided at wk7 The area above the mesonephric ducts is the vesicourethral canal The area below the mesonephric ducts is the urogenital sinus Mesonephric ducts drain into urogenital sinus therefore mesoderm becomes fused with endoderm. The ureters then evaginate from the mesonephric duct and will enter the bladder at day37 The trigone is formed by the dilatation of the mesonephric ducts terminus known as the common excretory duct. The overlying mesoderm migrates to the midline and this is the primitive trigone which is then covered by endoderm of the urogenital canal. 7. Anatomical land marks Left Kidney T11 to L2 Relations Spleen- supero-lateral Adrenal- supero-medial Tail of pancreas- Hilum Splenic flexure- inferior and anterior Right kidney T12-L3 Relations Liver-superior Adrenal supero-medial IVC D2 Hepatic flexure 8. Anatomical landmarks Ureter Emerge at hilum Posterior to vein and artery Lie at tips of transverse processes of vertebral bodies Crosses pelvic brim on SI joint and runs forwards at lower end of SIJ Lie anterior to the bifurcation of the common iliac vessels Run alongside internal iliac artery Run into tunnel of detrussor muscle to OU at lateral aspect of the trigone 9. Anatomical land marks 10. Duplex Renal disease Partial or total Bilateral 40 % 0.1% are complete F>M Majority asymptomatic 2-3% contrast studies Embryology Single ureteric bud- incomplete duplication 2 ureteric buds-complete Caudal bud inserts into inferior pole of metanephros and the UO is supero-lateral to trigone Cranial bud inserts into superior pole and UO is distal in bladder or can be in urethra 11. Renal Duplex Disease Pathology Upper pole obstructs- hydronephrosis and often dysplastic kidney and a ureterocele in bladder 12. Renal Duplex Disease Pathology Upper pole obstructs- hydronephrosis and often dysplastic kidney and a ureterocele in bladder Lower pole reflux- lack of detrussor tunnel Clinical presentation May be seen on neonatal scans May present with recurrent pyelonephritis May present with incontinence If lower pole orifice is below urinary sphincter Investigations USS MCUG-will show reflux 13. PUJ Obstruction A pelvo-ureteric junction (PUJ) obstruction can be thought of as a restriction to flow of urine, from the renal pelvis to the ureter, which, if left uncorrected, leads to progressive renal deterioration Congenital obstructive uropathy Broad spectrum of severity Varied natural history Resolution of prenatal hydronephrosis New onset PUJ obst in previously normal kidneys. 14. PUJO Dilated renal pelvis with narrowed tortuous segment of proximal ureter Pathology Intrinsic- defect in collagen fibres, circular muscle fibres Extrinsic-Aberrant renal vessels (lower pole) 15. PUJO-Presentation Prenatal USS dilation apparent from 2nd trimester Renal pelvis diameter >15mm in 2nd trimester 35-50% of all significant prenatal uropathy Incidental post natal finding 16. PUJO-clinical presentation Neonatal abdominal mass UTI- most common Loin Pain-after fluid load Adolescents after alcohol Late adults-diuretic meds Haematuria Hypertension 17. PUJO-investigations USS-assess renal pelvic diameter Good for surveillance Renogram Assess level of obstruction Indirect assessment of renal functionimportant for management decisions Contrast study Assess intrinsic obstruction Assess vasculature 18. PUJO-management Conservative Assymptomatic esp elderly Infants No renal impairment & No infections-as it may resolve Adults- No renal impairment and no symptoms Surgical Pyeloplasty Excision of constriction Remove excess renal pelvis Endoscopic Incision Expansion balloons- essentially bursting ureteric constriction 19. Calculi Why do patients get pain from stones? 20. Renal Calculi Why do patients get pain from stones? At which positions do stones cause problems? Hint start at the top 21. Renal Calculi Why do patients get pain from stones? At which positions do stones cause problems? Infundibulum PUJ Pelvic Brim Over Iliac Vessels VUJ 22. Questions