Q: Analyse this urodynamic study and comment A: I now have all the data I need from the images and textbook references. Let me compile a comprehensive analysis. --- Urodynamic Study Analysis — Bhatt, Sharad Male, 63 yrs, Patient 3379 Study: Pressure-Flow Study Date: 11/05/2026 Sujay Urological Hospital Dr. Ajay Bhandarkar --- Patient Demographics - Male, DOB 31/08/1962, age 63 - Classic demographic for BPH/LUTS evaluation --- FILLING PHASE Cystometric Data Parameter Value Interpretation --------- Infused volume 500 ml — Bladder filling 500 ml No leakage First sensation 82 ml Low normal: 100–200 ml — early first sensation First desire 130 ml Low normal: 150–250 ml Normal desire 254 ml Normal range Strong desire 494 ml Near maximum capacity Urgency 500 ml At maximum MCC 500 ml Normal normal: 300–600 ml Pdet throughout filling: Remained low 4–8 cmH₂O — flat cystometric curve. Bladder Compliance - Pdet compliance linear regression: 29.1 ml/cmH₂O Begin 2 ml → End 100 ml - Normal compliance ≥20 ml/cmH₂O is the accepted lower limit - No detrusor overactivity DO was detected on the trace during filling — the Pdet trace is flat and stable throughout the filling phase despite EMG spikes cough artefacts confirmed by simultaneous Pabd rises Cough Test / Artefact Analysis - Multiple cough markers recorded; Pves and Pabd spikes are synchronous, confirming good catheter placement and signal quality - Pdet remains low with coughs, confirming no stress incontinence leak or artefactual DO --- VOIDING PHASE Key Parameters Parameter Value Normal Male Interpretation ------------ Voided volume 184 ml — Low — partial void Total bladder capacity 501 ml — — Qmax 6.2 ml/s 15 ml/s Markedly reduced Time to Qmax 21 s — Prolonged Pdet at Qmax 38 cmH₂O — Elevated Average flow rate 2.6 ml/s 10 ml/s Markedly reduced Flow time 70 s — — Voiding time 130 s — Prolonged 130 s vs 70 s flow time Hesitancy 28 s 10 s Prolonged Computed residual PVR 317 ml 50 ml Significantly elevated VOID classification 6 / 180 / - — — --- NOMOGRAM ANALYSIS ICS Bladder Outlet Obstruction Index BOOI Formula: BOOI = Pdet@Qmax − 2Qmax BOOI = 38 − 2 × 6.2 = 38 − 12.4 = 25.6 - BOOI ≥40 = Obstructed - BOOI 20–40 = Equivocal - BOOI ≤20 = Unobstructed ➡️ BOOI = 25.6 → Equivocal zone borderline obstructed ICS Detrusor-Flow Plot - The plot on page 3 confirms the data point falls in the Equivocal/borderline Obstructed region - Obstructed slope: −1.67 cmH₂O/ml/s; A/G number: 26 — consistent with equivocal obstruction Bladder Contractility Index BCI Formula: BCI = Pdet@Qmax + 5 × Qmax BCI = 38 + 5 × 6.2 = 38 + 31 = 69 - BCI 150 = Strong - BCI 100–150 = Normal - BCI 100 = Weak ➡️ BCI = 69 → Significantly impaired detrusor contractility Weak Siroky Nomogram - Average flow rate of 3 ml/s at 184 ml bladder volume plots well below the -3 SD line → severely obstructed/poor flow - Qmax of 6 ml/s also plots in the below -3 SD range → confirms significantly abnormal voiding Liverpool Nomogram - Average flow rate and Qmax both plot in the lowest percentile bands — consistent with obstructed/severely impaired voiding --- INTEGRATED INTERPRETATION Primary Findings: 1. Detrusor underactivity DU — the dominant finding - BCI of 69 confirms markedly weak detrusor contractility - Despite generating 38 cmH₂O, the bladder cannot sustain adequate flow - Long hesitancy 28 s, prolonged voiding time 130 s vs 70 s flow time = significant abdominal straining period, interrupted voiding 2. Bladder outlet obstruction — equivocal - BOOI 25.6 = equivocal; the ICS nomogram and A/G number of 26 place this in the equivocal zone - Cannot confirm significant anatomical BOO e.g., BPH obstruction from urodynamics alone 3. Large post-void residual: 317 ml - Only 184/501 ml voided = bladder voiding efficiency of 37% severely impaired; normal 90% - Indicates chronically underactive bladder with incomplete emptying 4. No detrusor overactivity detected - Despite early first sensation 82 ml and urgency at 500 ml, the cystometric trace showed no phasic DO - Urgency without detrusor overactivity may represent sensory urgency 5. Normal bladder compliance 29.1 ml/cmH₂O - No upper tract risk from compliance alone --- CLINICAL DIAGNOSIS Detrusor Underactivity Underactive Bladder with possible equivocal Bladder Outlet Obstruction This 63-year-old male presents with a urodynamic picture dominated by impaired detrusor contractility rather than pure bladder outlet obstruction. The equivocal BOOI leaves open the possibility of coexisting BPO from BPH, which is common in this age group and could be contributing to the chronically elevated PVR and secondary detrusor fatigue. --- CLINICAL IMPLICATIONS & MANAGEMENT Issue Recommendation ------ Elevated PVR 317 ml Risk of UTI, upper tract deterioration if sustained — renal function assessment creatinine, USS renal tract DU dominant Alpha-blocker trial to reduce outlet resistance may help even in equivocal obstruction Surgical risk caution TURP/surgical desobstruction carries risk of worsening urinary retention if DU is the dominant pathology; pre-operative counselling essential Bladder retraining / CISC If conservative management fails, clean intermittent self-catheterisation CISC may be required Repeat UDS Consider after alpha-blocker trial to reassess voiding parameters Exclude neurological cause Given age and DU pattern, spinal/neurological pathology should be excluded if no BPH found on imaging --- References: Campbell-Walsh-Wein Urology 11th Ed, Chapter 114 — Urodynamics; Smith & Tanagho's General Urology 19th Ed, Chapter 29 — Voiding Pressure-Flow Studies. BOOI/BCI formulae per Abrams 1999, BJU Int 841:14–15. Q: Dj stent size according to age of patient in pediatric case A: Here is a comprehensive guide to DJ Double-J stent sizing in pediatric urology: --- Pediatric DJ Stent Size Selection Two Dimensions to Determine: Diameter French/Charrière and Length cm --- 1. Diameter Fr/Ch — by Age/Weight Age Group Weight Stent Diameter --------- Neonate / Newborn 1 month 3.5 kg 2.8–3 Fr Infant 1–12 months 3.5–10 kg 3–3.7 Fr Toddler 1–3 years 10–15 kg 3.7–4 Fr Young child 3–6 years 15–20 kg 4–4.7 Fr Older child 6–10 years 20–30 kg 4.7–6 Fr Pre-teen/Adolescent 10–16 years 30–50 kg 6 Fr Adolescent ≥16 yrs / Adult size 50 kg 6–7 Fr Practical rule: Use the smallest diameter that can be safely negotiated past the ureteral orifice — never force a larger stent, as ureteric trauma and orifice disruption are serious risks in small children. Specific clinical notes: - Neonatal pyeloplasty: 2.8–3 Fr DJ stents are well described; antegrade insertion intraoperatively is preferred - Ureteroscopy in 5 years: 3–4 Fr is the range; passive ureteral dilation or mini-ureteroscopes 4.5 Fr may be needed first - PUJ obstruction hydronephrosis: 3–4.7 Fr multi-length polyurethane stents are used for endoscopic stenting as an alternative/bridge to pyeloplasty --- 2. Length cm — by Age Formula Society of Pediatric Urology, SPU: Stent length cm = Patient age years + 10 Age Formula Result Recommended Length Notes ------------ Neonate 0–1 mo — 10–12 cm Formula not applicable; use 10 cm 1–6 months — 10–12 cm — 6–12 months — 12 cm — 1 year 11 cm 12 cm Round up 2 years 12 cm 12–14 cm — 3 years 13 cm 12–14 cm Formula tends to overestimate in ≤3 yrs; use age + 10 − 2 4 years 14 cm 14 cm — 5 years 15 cm 14–16 cm — 6 years 16 cm 16 cm — 8 years 18 cm 18 cm — 10 years 20 cm 20 cm — 12 years 22 cm 22–24 cm — 14+ years 24 cm 24–26 cm Transition to adult sizing Modified formula for infants ≤3 years: Stent length cm = Age in years + 10 − 2 This corrects for the tendency of the standard formula to produce stents that are too long in very young children — a stent too long can curl into the urethra and cause urethral irritation or reflux. --- 3. Quick Summary Chart Age Diameter Length --------- Neonate 2.8–3 Fr 10–12 cm 1–6 months 3 Fr 12 cm 6–12 months 3–3.7 Fr 12 cm 1–2 years 3.7–4 Fr 12–14 cm 3–5 years 4–4.7 Fr 14–16 cm 6–8 years 4.7–6 Fr 16–18 cm 9–12 years 6 Fr 20–22 cm 12–16 years 6 Fr 22–26 cm --- 4. Important Practical Points - Fluoroscopic/ultrasound confirmation of stent position is essential in all pediatric cases — visual inspection alone is unreliable - Image-guided sizing: Where available, pre-op CT or ultrasound measurement of the renal pelvis to ureterovesical junction distance is the most accurate guide to stent length - Avoid over-length stents in infants/toddlers — can coil into the urethra; avoid under-length — risk of stent migration proximally well described in neonatal pyeloplasty - Material: Soft polyurethane or hydrophilic-coated stents e.g. 3–4.7 Fr multi-length are preferred for patient comfort - Dwell time: Typically 4–12 weeks depending on indication pyeloplasty: 6 weeks; stone: 4–6 weeks - Removal: Under GA in children; 9.5 Fr pediatric cystoscope with grasping forceps --- References: Society of Pediatric Urology SPU Abstract, 2018 — Stent Length Formula Validation; Dove Medical Press — Choosing the Right Catheter for Pediatric Procedures, Res Rep Urol 2020; Pogorelić et al., Can J Urol 2017 3–4.7 Fr DJ stents in pediatric hydronephrosis.
