“Advances in Stone Disease Management” Innovative Treatments Exceptional Service Superior Outcomes “Advances in Stone Disease Management” Casey McCullough, DO, MBA, FACOS

Disclosures None

Learning Objectives Identify the factors that increase the risk for sepsis and urgent Urologic management in the stone patient Understand the evaluation of patients presenting with renal colic and irritative urinary symptoms manifesting as stone disease Discuss the surgical approaches available in treating renal, ureteral, and bladder calculi

Stone Disease Prevalence approximately 9% of U.S. population Annual U.S. cost burden - $5 Billion dollars! Prevention is the cornerstone of all therapy Acute surgical intervention for the symptomatic patient Constant improvement in Endoscopic technology

Epidemiology Incidence of stone disease peaks in 4th to 6th decade Men historically have 2 or 3 times the risk than women Caucasian men/women have highest risk African-American men and Asian women have the lowest risk Dramatic increase in the pediatric population, possibly related to childhood obesity

Environmental Factors Hot, dry climates Highest prevalence of stones is in the Southeast Occupations with exposure to excessive heat Conditions that promote dehydration

Systemic Factors Obesity, weight gain, metabolic syndrome Type II Diabetes, Insulin Resistance, Dislipidemia, HTN Woo Y, et al. Metabolic Syndrome and Kidney Stone Disease: A Systemic Review. J Endourol, 30(3), March 2016, 246-53.

Calcium Stone Disease RISK FACTORS: ↓ urine volume ↓ or ↑ urine pH ↑ urinary excretion of calcium, oxalate, & uric acid ↓ urinary excretion of citrate

Urine Evaluation Urinalysis – presence of crystals can be pathognomonic for stone composition Hexagonal – Cystinuria ; Coffin-Lid – Struvite Urine Culture: Urease splitting organism (proteus, klebsiella) – struvite stones Urine pH pH < 5.5 = uric acid stones pH > 7.0 = struvite or calcium phosphate stones

Metabolic Evaluation

Radiographic Evaluation Historically plain abdominal radiography and intravenous pyelography Renal Ultrasound Unenhanced Helical CT scan: stone burden, collecting system anatomy, location, extravasation, stranding Hounsfield Unit density (HU): 1,000 HU Skin to Stone Distance (SSD): >10cm

Radiographic Evaluation

The Acute Stone Episode History and Physical Examination: Fever >100F, Tachycardia, Hypotension: concern for impending Sepsis Laboratory Evaluation: CBC, BMP, blood cultures, urine culture Radiographic evaluation Pain control: NSAIDs and Opioid analgesics. Ketorolac. NSAIDs directly inhibit prostaglandins, decreasing activation of pain receptor, reducing renal blood flow and ureteral contractions.

The Acute Stone Episode Management of ureteral obstruction in the septic patient is urgent decompression of the collecting system Ureteral Stent Nephrostomy tube placement (PCN)

Medical Expulsive Therapy (MET) No signs of infection, normal renal function, well-controlled pain, reasonable likelihood of spontaneous stone passage Tamsulosin 0.4mg daily (off label, intra-operative floppy iris syndrome, hypotension, nasal congestion) Length of time using MET is patient dependent

Shock Wave Lithotripsy (ESWL) Physics: repetitive administration of shock waves, with both positive and negative pressure components, creates small fractures in the targeted stone. 2,500 to 3,000 shocks during a treatment session leads to stone fragmentation Electrohydrolic (EHL), Electromagnetic, and Piezoelectric generators Imaging: Fluoroscopy or Ultrasound technology

Shock Wave Lithotripsy (ESWL) Indications: Location of stone within the kidney. Lower pole stones have lower success rate. Location in the Ureter decreases stone free rate. 72% ESWL vs 90% URS Not recommended for distal ureteral stones because lower stone free rates Ureteral stenting not required Stone size is greatest predictor of SWL success. As stone size increases, SWL success rates decline. In general, stones <10mm

Shock Wave Lithotripsy (ESWL) Stone Composition affects the ease at which it fragments with SWL Cystine (Most Resistant) Brushite Calcium oxalate monohydrate Struvite Calcium oxalate dihydrate Uric acid stones (Least Resistant)

Shock Wave Lithotripsy Acute Complications Renal Injury: Hematoma, contusion. 1-20% Nearly all patients post ESWL will have some degree of gross hematuria Steinstrasse: “street of stones”, the accumulation of stone fragments in the ureter post ESWL. Stent placement does NOT reduce occurrence! HTN: increased age >60yrs old associated with higher risk of development DM: one retrospective long term study Pregnancy: absolute contraindication

Shock Wave Lithotripsy Acute Complications

Percutaneous Nephrolithotomy (PCNL) Reserve for large (>2cm) & complex stones, Staghorn calculi, or stones with complex renal anatomy All patients need a sterile urine culture prior or been treated with culture specific antibiotics Percutaneous kidney access obtained through a posterior calyx Lithotripsy performed through rigid nephroscope and ultrasonic/pneumatic technology

Percutaneous Nephrolithotomy (PCNL)

PCNL Complications 4 – 61% Septic – bacteremia occurs up to 37% post-op, 74% rate of post-op fever Hemorrhagic – 0.4 – 11%. If delayed: pseudoaneurysm, AV fistula, or segmental renal artery injury Visceral injury: pleura, liver, spleen, colon, duodenum What is the irrigant of choice for all upper endoscopic urologic procedures?

PCNL Video

Semi-Rigid Ureteroscopy (URS) Generally used to treat ureteral stones below the iliac vessels Safety wire used to maintain access Stones can be basket extracted or broken up with Holmium laser fiber Flexible quartz fiber, 150-1,000 microns, photothermal direct contact Usually requires ureteral stent placement afterwards

Semi-Rigid Ureteroscopy (URS)

Semi-Rigid Ureteroscopy Complications Perforation: terminate the procedure and place a ureteral stent Extrusion of stone fragments Avulsion: <1% risk Infection / Sepsis Stricture: 0.5-4% risk. Risk factors include impacted ureteral stone and/or ureteral injury

Semi-Rigid Ureteroscopy Video

Flexible Ureteroscopy Used to treat all appropriate renal calculi or ureteral stones above the iliacs Staged procedures to treat large renal stones >2cm Smaller working channel than semi-rigid ureterscopes (3.6Fr) Post-operative stent placement Similar complications to semi-rigid ureteroscopy

Open/Laparoscopic/Robotic Stone Surgery Anatrophic Nephrolithotomy Pyelolithotomy Caliceal Diverticulolithotomy Ureterolithotomy Nephrectomy

Robotic Pyelolithotomy and Stone Extraction

Renal Calculi Staghorn Calculi Non-Staghorn, Non-Lower Pole PCNL is first line therapy Should NOT be observed if patient is healthy enough Non-Staghorn, Non-Lower Pole <2cm: URS or SWL >2cm: PCNL

Selection of Therapy Staghorn Calculi: PCNL is 1st line therapy. Should not be observed if healthy Non-staghorn, Non-lower pole stones: Majority of renal stones. SWL or URS 50% of asymptomatic stones will progress (Elective surgery or observation) Lower Pole Renal Calculi: SWL, URS, PCNL. Superior stone free rates for URS for stones <2.5cm in size Ureteral Calculi: URS Bladder Calculi: holmium laser lithotriopsy or ultrasonic treatment

Conclusion of Surgical Management Surgical management of stone disease should be tailored to the patient and the stone. Certain patient and stone characteristics can preclude certain types of therapy

References

Medical Management Involves the initiation of dietary measures and medications to reduce the risk of stone recurrence in - Recurrent - Interested first-time stone formers Basis for recommendations may be empiric or based on stone composition

Calcium Oxalate and Phosphate Increase fluid intake for a goal urine output >2.5 L daily Avoid strict dietary calcium restriction Consume the RDA of calcium - Women <50 yrs and men <70 yrs – 1,000mg daily - Women >50 yrs and men >70 yrs – 1,200mg daily Limit sodium intake to <100 mEq daily Oxalate-rich foods in moderation (spinach, potatoes, nuts, tea, chocolate)

Calcium Oxalate and Phosphate Calcium intake modulates urinary oxalate excretion by binding oxalate in the intestine Animal protein (red meat, fish, poultry, pork) confers an acid load that can reduce urinary citrate excretion & provides a purine load that increases urinary uric acid Fruits and vegetables provide alkali, enhancing urinary citrate excretion

Pharmacologic Therapy - THIAZIDES Promote net calcium reabsorption in distal renal tubule, thus reducing urinary calcium Primarily for Hypercalciuric stone formers Check 24 hour urine Ca+ levels (Litholink) Hydrochlorothiazide, Chlorthalidone, Indapamide Adverse Events: Hypokalemia, hypocitraturia

Primary Hyperparathyroidism Always check PTH, uric acid, serum Ca+ levels Primary hyperparathyroidism due to parathyroid adenoma are treated surgically

Uric Acid Stones No RCT’s assessing effect of dietary or pharmacologic therapy Low urine pH (<5.5) most common abnormality Use Potassium Citrate (30-60mEq) to alkalinize urine Use of Allopurinol rarely necessary: when pH >6.0, total uric acid concentration must exceed 1000mg/L to exceed solubility limits

Struvite Stones Magnesium, Ammonium, Phosphate stones Dietary therapy with high fluid intake Acetohydroxaminic acid: irreversible urease inhibitor to reduce urine pH and ammonia levels, but high side effect profile (HA, GI, anemia)

Cystine Stones Limit of solubility of Cystine is 250mg/L Increase urine pH to 7-7.5 with Potassium Citrate Cystine-binding Thiol drug / Thiola / Alpha mercaptoproprionyl glycine (GI side effects, monitor CBC and LFTs) Avoid high animal protein intake to limit cystine substrate methionine and prevent low urine pH

Follow-Up Stone formers managed with diet and drug therapy should be monitored - Imaging studies to identify growth or recurrence - 24-hour urine to monitor response to therapy (Litholink) Frequency of imaging and urine testing tailored to disease aggressiveness - generally every 6 months

References Borghi, L. et al., Urinary volume, water, and recurrences in idiopathic calcium nephrolithiasis: a 5 yr randomized prospective study. J Urol, 1996. 155(3): p 839-43. Pearl, MS, et al., Medical Management of Kidney Stones: AUA Guideline. J Urol, 2014. 192(2): p 316-24. Borghi, L. et al., Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria. N Engl J Med, 2002. 346(2): p 77-84.

T. Casey McCullough, DO, MBA, FACOS Snellville, Johns Creek, Lawrenceville, Decatur, Alpharetta, Sandy Springs, Athens, Dunwoody, Kennesaw Thank You! T. Casey McCullough, DO, MBA, FACOS (860)389-2943 cell tmccullough@urologygeorgia.com 10730 Medlock Bridge Rd John’s Creek, GA 30097 (678)344-8900 office www.UrologyGeorgia.com