Pelvi-Ureteric Junction Obstruction Revisited

Dr. Bimalendu Mukherjee was trained in Urology in the UK between 1956 to 1961. Upon return to India, he took up a teaching position in Calcutta National Medical College and ultimately retired as Professor of Surgery. He took active role in promoting Urology as a separate discipline and a Dept. of Urology was subsequently developed in this Institute. Almost all his post graduate trainees were guided for their dissertation in Urological topics including Cadaveric studies of Renal Anatomy to improve PCNL puncture guidelines in our country. This was in late 1980s. He became the President of West Bengal Chapter of USI and was instrumental in initiating MCh (Urology) in Calcutta University. The final spring board of this initiative was his endeavour as the organising person of USICON in Kolkata in 1984. He later became the president of USI. 1996.

Pelvi-Ureteric Junction Obstruction Revisited Dr S S Joshi MS. FRCS Consultant Urologist / Paed. Urologist Jaslok Hospital & Research Centre

PUJn Obstruction Defined as blockage of ureter at renal pelvis In children majority congenital with extrarenal pelvis Childhood 1:1000 Boys : Girls = 2:1 in the new born Left side > Right side : bilateral 10-40% Associated VUR 14-20% (Gr 2)

PUJO and MCUG Unilateral PUJO no MCUG Bilateral PUJO with recurrent UTI Dilated ureter on imaging especially post void Strong H/o sibling VUR > gr3

Aetiology Intrinsic Smooth muscle defect at PUJ leading to aperistaltic segment Stenosis of the upper end of ureter High insertion of ureter on pelvis -? Primary?Secondary Extrinsic Lower polar aberrant vessels

Clinical presentation in PUJO Presently most diagnosed on antenatal USG Later if missed antenataly commonly seen as febrile UTI Haematuria both gross or commonly microscopic Abdominal discomfort/ache, after food or diuresis Lump in abdomen, tender kidney

IVU in Children 1ml/kg contrast, minimum 10 ml Prone picture essential Delayed films SOS Hydrated child, NO DEHYDRATION

NEONATAL HYDRONEPHROSIS 4.3 3.2 2.1 9.1 13 4.3 64 PU OBST U.V. JN OBST VUR NORMAL MCK NFK PUV

Etiology of urinary tract dilation detected on antenatal ultrasound Etiology Incidence (%) Transient/physiologic 50-70 Ureteropelvic junction obstruction 10-30 Vesicoureteral reflux 10-40 Ureterovesical junction obstruction / megaureter 5-15 Multicystic dysplastic kidney disease 2-5 Posterior urethral valves 1-5 Ureterocele, ectopic ureter, duplex system, urethral atresia, Prune belly syndrome, polycystic kidney diseases, I cysts Uncommon Adapted from Nguyen et al. 2010

BASIC ANATOMY AND PHYSIOLOGY OF ANTENATAL USG: (1) Urine production at 9 weeks >14 weeks 2/3 rd of amniotic fluid is foetal urine. In 2-3 trimester bladder fills, empties every 25-30 mts. Bladder is always between two umbilical arteries. USG- identify spine & kidneys are parasagital. Normal condition foetal ureters are not seen. >18 weeks CMD is well seen.

POSTERIOR URETHRAL VALVES

NORMAL FINDINGS ON USG AT VARIOUS GESTATIONAL PERIODS Time at presentation 16-27 wks >28 wks Post natal >48 wks APD <4 mm <7 mm <10 mm Calyceal Dilt Nil Nil Nil Parenchymal Thickness Parenchymal appearance Ureters N N N N N N NOT SEEN Bladder N N N Amniotic fluid N N N.A.

SFU Hydronephrosis criteria gr 0 gr1 Ultrasound grade Pelvis 0 Not Imaged 1 Intrarenal (Thin stripe) Minor Calyces Not Imaged Not Imaged Parenchyma Intact Intact gr2 2 2.1 Extrarenal pelvis Intrarenal (Broad stripe) Extrarenal Not Imaged Not Dilated Intact Intact gr3 2.2 Dilated major calyces Extrarenal 3 Extrarenal Not Dilated Uniform Dilation Intact Intact gr4 3.1 Extrarenal 4 Extrarenal Uniform Dilation Uniform Dilation Intact Thin

Parenchymal thickness Perinephric collection Internal echos /stones A.P. diameter Non visualised ureter Dilated calyces (minor) Multiple dilated calyces communicating with each other and with a medially placed larger cyst -> the dilated renal pelvis

DIFFERENTIAL DIAGNOSIS OF PUJn OBSTRUCTION: Postnatal Main D/D of PUJO is non obstructive dilatation. Multicystic Dysplastic Kidney. Megacalycosis (medullary hypoplasia; calyces >>> pelvis) Infundibular stenosis UVJ obstruction

Treatment Options 1. Conservative management 2. Open Anterolateral Lumbotomy 3. Laproscopic 4. Robot assisted

Conservative management in PUJO APD 20-30 mm APD < 15 mm rarely needs surgery. Differential function 40% or more, drainage curve normal or indeterminate type, no deterioration of differential function on repeat renogram, T ½ normal Normal cortical transit time. No UTI, O/E NAD, no stones.

Indications for pyeloplasty on USG Significant functional impairment <40% on radionucleide scan Gross hydronephrosis AP diameter >30 mm (Gr III/IV SFU)

PUJ INFECTION

8 years/male child. Presented with pain and hematuria. X-ray KUB showed right renal calculus and multiple secondary left renal calculi. Right renal pelvic calculus Multiple secondary left renal calculi IVU: Bilateral good function with right renal calculus and left PUJO with secondary left renal calculi.

5 years post-op IVU: Bilateral good function with good drainage on left side

Dynamic Renography I 123- hippurate, Tch-MAG3, Tch-EC Tch- DTPA tubular extraction tubular extraction tubular extraction filtration estimation of DRF estimation of DRF estimation of DRF Post renal transplant dynamic dynamic dynamic dynamic

From a nuclear medicine aspect, it is only deterioration (10%) on sequential studies that is an indication for surgery. Stable function, even if reduced, is an indication to maintain a conservative watchful approach. Split function is a robust and reproducible parameter. It is the most critical measurement for management of prenatally diagnosed unilateral PUJ dilatation. Cortical transit time is defined as a physiological transit of the tracer through the parenchyma into the pelvis, & delayed transit time is a strong indicater for surgery.

TTT (cortical transit time-ctt) of 99mTc-MAG3was classified as timely, delayed or indeterminate based on visual assessment. Timely TTT was defined as a physiological transit of the tracer through the parenchyma into the pelvis, Delayed as an unphysiological and clearly slowed transport. Indeterminate when it was impossible to arrive at a definite classification.

Cortical phase Timely TTT

Cortical phase Delayed TTT

Nuclear Medicine Parameters in PUJO Parameters used in renography for evaluation of unilateral obstruction are Split function: In older children, a 5% change; & in young infants upto 10% is considered significant Post diuretic curve pattern T1/2; Tmax Sequential image evaluation Cortical transit time Supranormal differential function Delayed image taken at 1hr

Indication for Surgery AP diameter >30 mm, calyceal dilatation with thinning parenchyma opposite dilated calyx, stone or debris, perinephric collection, no ureteric dilatation Decreasing split renal function on follow up 10%, split function <40%, increased T1/2 transit time, obstructive drainage pattern Delayed cortical transit time Parenchymal thickness Supra normal differential function Palpable lump Clinical S/S, Urinary tract infection, secondary stones Internal echos stones Non visualised ureter Dilated calyces (minor)

Surgical Options 1. Open Anterolateral Lumbotomy 2. Laproscopic 3. Robot assisted

Male child 4 months Antenatal USG showed lt sided HN Routine post natal USG done at 4 mths One episode of UTI C/S +ve. Now asymptomatic child, thriving well

24 weeks antenatal USG, primi 29 yrs, IVF baby, normal amniotic fluid, bladder normal

Day 4 post natal

6 weeks post natal

Post Op 3 month

Bilateral PUJn. Obst. AP diameter Right (cms) Left (cms) Antenatal 0.9 0.6 Postnatal 5 days 2 1.8 Post natal 6 weeks 3.16 (palpable lump) 1.8 Post operative 3 months 1 1.6 Post op 1 Year 0.6 1.2 Post op 1.5 Years 0.5 (cortical thickness 6mm) 1 (cortical thickness 6mm)

Bilateral Pujn. Obst. Split renal function on renogram Split Function Right Left Post natally pre op 57.5% 42.3% (both obstructed curve) Post op 3 months 53.1% 46.9% (R) normal (L) obstructed Post op 18 months 47.3% 52.6% (R) normal (L) obstructed

Nov 2017

Upper 1/3 blood supply

2mg/kg 0.25% sensorcaine infiltrate

18 month old child from Bangladesh No antenatal history available Presented at 3 months with dribbling of urine and crying during micturition with fever Managed conservatively 6 months age presented with abdominal distension and similar urinary complaints USG showed gross HU and HN

Patient was then subjected to Right PCN insertion on 8/11/16, which was removed after 2 weeks Further to this, patient was posted for Right? Pyelolysis with DJ stenting on 6/2/17 Developed SSI -> secondary suturing of wound+right DJ removal done on 23/3/17 Patient underwent MCUG & DMSA Renal Scan at 1 year of age

Follow up Post Pyeloplasty CAP for 3 wks, Rpt urine c/s JJ stent removal 2-3 wks USG of KUB at 6 months or earlier if UTI, renal ache Tch EC renogram with lasix at 1 year Repeat USG at 2 years; if improved, asymptomatic Discharge