DIAGNOSTIC IMAGING AND MINIMALLY INVASIVE MANAGEMENT OF URINARY TRACT DISEASE Andrew Weissman, VMD, DACVR Carley Allen, DVM, Practice Limited to Internal Medicine Diagnostic Imaging Interventional Radiology Red Bank Veterinary Hospital Red Bank Veterinary Hospital Outline • Introduction to interventional radiology • Overview of normal urinary tract anatomy • Bladder stone diagnosis and management • Canine malignant urethral obstructions • Canine benign ureteral obstructions • Feline benign ureteral obstructions Introduction ■ What is interventional radiology? – Image-guided interventions for various diseases in the body ■ Equipment needed – C-arm fluoroscopy unit, ultrasound – Appropriate rigid and flexible endoscopes – Various tools ■ catheters, guidewires, access sheaths, stents, etc… Lillie 10yo FS Maltese Mix ■ Hematuria ■ U/A free catch – struvite crystals, WBCs, blood ■ Started Clavamox Cystocentesis ■ Panel Name URINALYSIS ■ COLLECTION METHOD CATHERIZED COLOR YELLOW CLARITY HAZY SPECIFIC GRAVITY 1.017 GLUCOSE NEGATIVE BILIRUBIN NEGATIVE KETONES NEGATIVE BLOOD NEGATIVE PH 6.0 PROTEIN NEGATIVE UROBILINOGEN NORMAL WBC 2-3 HPF RBC 4-10 HPF BACTERIA NONE SEEN EPI CELL NONE SEEN MUCUS NONE SEEN CASTS NONE SEEN FEW STRUVITE CRYSTALS SEEN Calcium Oxalate ■ What – 41% of stones (Minnesota 2007) – Appearance ■ Who – 73% males – Bichon, miniature schnauzer, yorkie, shih tzu, lhasa – Goldens, GSD, cockers have *decreased* risk – Mid-age to older – Cushings, hypercalcemia – Exogenous steroids, furosemide ■ Environment – Acidic pH (< 7.0) – Typically sterile Calcium Oxalate ■ Dietary dissolution not possible ■ Stone removal required ■ Prevention – Prevention diets ■ Royal Canin SO – Potassium citrate 75 mg/kg BID ■ Target urine pH 7.5 – Thiazide diuretics (hydrochlorthiazide 1 (cat) – 2 (dog) mg/kg PO q 12) ■ 50% rate of stone recurrence within 3 years of initial diagnosis Voiding Urohydropropulsion Benefits Limitations ■ Minimally invasive ■ Size of patient vs stone size ■ Number of stones doesn’t matter – Dog ■ Female – 4-5 mm, up to 10 ■ No post-procedure incision care ■ Male – 2-3 mm, up to 5 ■ Same-day discharge – Cat ■ Female – 2mm, up to 5 ■ Male – 1 mm – Rule of thumb: smooth stones up to 5mm ok in dogs >9 kg ■ Stone type/shape – Struvite vs CaOx ■ Do NOT attempt if already obstructed Voiding Urohydropropulsion ■ Let gravity work for you! ■ Pass urinary catheter ■ Fill bladder with sterile saline ■ Agitate bladder ■ Elevate head ■ Manually compress bladder ■ Collect stones in sterile container for submission to lab ■ Repeat until 3 clean expressions in a row ■ Repeat single lateral AXR Webb et al, Can Vet J 2014 Voiding Urohydropropulsion ■ Risks/Complications – Hematuria common post-procedure - < 24 hours – Abdominal bruising – Lodging stone within urethra – Bladder rupture – uncommon ■ Troubleshooting – Difficult to obtain solid urine stream – two-handed compression – Urethral obstruction – empty bladder first before retropulse stone ■ Can this be done in GP? YES! Adonis ■ 13yo MN Bichon ■ Straining to urinate, acutely worse ■ ADR, lethargic, inappetent ■ Marty piserchia ■ Tyler anderson Urethral Ultrasound Laser Lithotripsy ■ Equipment – Cystoscopes ■ Rigid and flexible – Ho:YAG laser – Stone retrieval baskets Laser Lithotripsy Benefits Limitations ■ Minimally invasive ■ Size of patient – 8 Fr must fit ■ Quicker time to discharge – Small dogs – Male cats ■ No post-procedure incision care ■ Number of stones ■ Equivalent rate of recurrence to cystotomy ■ Bleeding disorders ■ UTI – inc risk of recurrence ■ Excessive hematuria ■ Who has higher chance of success? Females! ■ 100% of female dogs and 87% of male dogs had complete stone removal ■ 14% of dogs required in-dwelling urinary catheter placement for 1-5 days post-procedure – 7% - partial or complete obstruction from swelling – 7% - prophylactically placed for anticipated pain/urethral spasm ■ Laser perforation of bladder wall (n = 2) ■ Bladder perforation during VUH (n = 2) ■ Urethral obstruction up to 5 days after procedure (n = 2) ■ 19% recurrence of stones, median 10.5 months post-lithotripsy – Male dogs’ stones recurred significantly quicker than females Male Cystoscopy With Urethroliths Laser Lithotripsy Male Urethrolith Basket Retrieval Male Urethrolith Maeve ■ 5yo FS Jack Russell Terrier ■ Pollakuria, stranguria ■ rDVM staph UTI pH 7.0 ■ 1 month recheck – hematuria, pollakuria, inappetence Struvite ■ What – Magnesium, ammonium, phosphate – 41% of stones (Minnesota 2007) – Appearance ■ Who – 85% females – Miniature schnauzer, yorkie, shih tzu, bichon, cocker, lhasa, lab, dachshund – Younger age at onset ■ Environment – Alkaline pH (> 7.0) – Concurrent infection (dog) >90% ■ Urease-producing bacteria ■ Staphylococcus, Enterococcus, Proteus – Struvite crystals do NOT predict stone Struvite ■ Dissolution ■ Stone removal – Diets – When should we think about this? ■ Hills S/D diet* ■ Obstruction ■ Hills C/D diet ■ Inadequate contact with urine ■ Royal Canin SO diet ■ Refusal to eat diet ■ Continue until 1 month after ■ Contraindication to eating diet dissolved – Pancreatitis – Antibiotics – Severe heart dz ■ Until 2-4 weeks beyond stone – Renal insufficiency resolution – Hypertension – Acidifiers? – Particularly good candidates for ■ D,L - methionine 75-100 mg/kg BID voiding urohydropropulsion – Time frame ■ Prevention ■ Small stones – 2-3 weeks – Infection-associated – UTI ■ Larger stones – 2-3 months prevention! – Sterile – diet Harry ■ 12yo MN Mini Poodle ■ Bladder stones for past 10 years – asymptomatic ■ Royal Canin SO ■ Stones got smaller? ■ Obstructed at rDVM ■ UA and UCS Panel Name URINALYSIS COLLECTION METHOD CATHERIZED COLOR YELLOW CLARITY CLEAR SPECIFIC GRAVITY 1.024 GLUCOSE NEGATIVE BILIRUBIN NEGATIVE KETONES NEGATIVE BLOOD NEGATIVE PH 5.5 PROTEIN NEGATIVE UROBILINOGEN NORMAL WBC 0-2 0-5 HPF RBC 0-2 HPF BACTERIA NONE SEEN EPI CELL NONE SEEN MUCUS NONE SEEN CASTS NONE SEEN CRYSTALS NONE SEEN UCS – NO GROWTH Cystotomy ■ 10-20% incomplete surgical removal of stones – Lack of distension of bladder – Hemorrhage – Mucosal edema – Small size ■ 37-50% complication rates reported ■ Unable to address lodged urethral stones ■ 40-60% stone recurrence rate – CaOx – Urate – Cystine ■ Minimally invasive options? Percutaneous Cystolithotomy (PCCL) ■ Minimally invasive cystotomy ■ Equipment necessary ■ Indications – Rigid + flexible cystoscope – Large number or size of stones – 6mm screw trocar – Small patient – Stone retrieval basket – Basic surgery pack ■ Other reasons to do PCCL approach – +/- cystoscopic biopsy forceps – Retrieving embedded urethral stones in small male dogs and female/male cats – When retrograde access not possible – Ureteral stenting in small male dogs – Evaluation of UVJ for upper urinary tract hematuria/IRH – Urethral stenting in male cats Percutaneous Cystolithotomy Benefits Limitations ■ Minimally invasive ■ UTI ■ Does not require abdominal CO2 – MUST have negative urine insufflation culture or be abx for 48 hours ■ Quicker time to discharge ■ Cost of procedure and equipment availability ■ Higher success rate – 96.3% ■ Typically need trained individual to ■ Ability to intervene with lodged assist intra-operatively urethroliths ■ Ability to detect smaller changes within bladder – Small stones – Small masses Langston et al, Compendium 2010 Langston et al, Compendium 2010 PCCL – Basket Retrieval PCCL – Bladder Mucosa Irregularity PCCL – Male Urethra Evaluation Long-Term Follow Up ■ Prophylactic antibiotics for 5-7 days post-procedure, NSAIDs x 7days ■ Recheck incision at 10-14 days ■ Alterations in diet and supplements based on stone analysis ■ Investigation into potential predisposing causes ■ Recheck radiographs 1 month after procedure ■ Recheck radiographs, urinalysis, and culture q 3 months Alfie ■ 8 yo MN Schnauzer ■ Chronic stranguria, pollakuria ■ Previous ultrasound showed questionably enlarged prostate gland Pumpkin ■ 8 yo MN Mix ■ Pollakuria, stranguria, hematuria Maggie ■ 10yo FS Lab ■ 2-3 day history of anorexia, lethargy, vomiting ■ Tense abdomen ■ Enlarged urinary bladder on palpation Indications for Stenting • Benign urethral obstructions • Urethral stricture • Urethral stones • Trauma • Reflex dyssynergia • Proliferative urethritis • Malignant urethral obstructions • Urinary tract transitional cell carcinoma (TCC) • Prostatic carcinoma Malignant Urethral Obstructions Weisse et al, JAVMA 2006 McMillan et al, JAVMA 2012 Blackburn et al, JAVMA 2013 No. of Dogs 12 (all obstructed) 19 (15 complete, 4 partial) 42 (32 complete, 11 partial) Success Rate 100% 89% 97.6% Interventions COX inhibitors, no chemo 11/19 treated before, 17/19 after Variable* MST from 153 (24-920) 108 (7-1,226) Diagnosis (days) MST from Stent 20 (mean 32, range 6-105) 78 (2-366) 78 (7-536) broken down by (days) treatment* Incontinence Rate 25% 41% (35% females, 50% males) 64% (47% females, 78% males) UTI Rate 35% Stranguria Rate 25% mod-severe, 40% mild Subjectively improved (median 42% score from 4 to 1) COD from re- 17% 18% 12.8% obstruction Median Survival Post-Stent • Stent only - 43 days (mean, 31) • NSAIDs only – 70 days (mean, 100) • Chemo post-stent – 90 days (mean, 133) • NSAIDs pre-, chemo post-stent – 251 days (mean, 231) Urethral Stent Placement Courtesy of Tracy Hill, DVM, DACVIM Final Product Courtesy of Tracy Hill, DVM, DACVIM Bella ■ 12 yo FS DSH ■ Senior wellness at rDVM ■ BUN 42 Creat 2.0 ■ Abdominal mass palpated • Diagnosis of Ureteral Obstruction • Radiographs +/- contrast • Abdominal ultrasound • Renal pelvis size • >13 mm – definitive • 7-13