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Chapter 7 · Central Ohio Urology Group · Ohio

Nephrolithiasis (Kidney Stones)

Stone disease is common, recurrent (roughly 50% recurrence within 5–10 years without prevention), and often exquisitely painful. Manage the acute episode (pain, obstruction, infection), decide who needs intervention, treat definitively, and then…

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Ohio: ureteroscopy is performed in our Columbus ASC. An obstructing stone with infection goes to the hospital, never the ASC.

Didactics

Shared across all locations

Stone disease is common, recurrent (roughly 50% recurrence within 5–10 years without prevention), and often exquisitely painful. Manage the acute episode (pain, obstruction, infection), decide who needs intervention, treat definitively, and then actually set up prevention so patients do not keep coming back.

7.1 Acute renal colic

Presentation — sudden, severe, colicky flank pain that waxes and wanes and may radiate to the groin, labia, or testis as the stone moves distally. Nausea and vomiting are common (shared celiac plexus innervation). The patient is classically restless and cannot find a comfortable position — a useful discriminator from peritonitis, where patients lie still. A stone at the ureterovesical junction produces urgency and frequency that mimics a UTI.

Diagnosis — non-contrast CT of the abdomen/pelvis is the standard — it defines stone size, location, density (Hounsfield units, which predict fragility), skin-to-stone distance, and the degree of hydronephrosis. Ultrasound (radiation-sparing) is preferred in pregnancy and reasonable for younger patients and for follow-up. Plain KUB is useful only for tracking a known radio-opaque stone (uric acid stones are radiolucent).

Labs — urinalysis (hematuria is present in ~85% — its ABSENCE does not exclude a stone), urine culture, CBC, creatinine. Check calcium and consider PTH later if hypercalcemia.

The stone emergency — never miss it

  • Fever or signs of infection with an obstructing stone = obstructive pyelonephritis/urosepsis → emergent decompression (stent or nephrostomy) plus antibiotics (Chapter 2). Antibiotics alone will not save this patient.

  • Also escalate: acute kidney injury, bilateral obstruction, obstruction of a solitary or transplanted kidney, or intractable pain/vomiting.

  • The patient who looks “not that sick” with a fever and an obstructing stone can be in septic shock in three hours. Do not send them home.

7.2 Acute management

7.3 When to intervene, and how — the Advanced Urology approach

Intervene for stones unlikely to pass, refractory pain, obstruction with infection (emergent), AKI, a solitary kidney, or patient preference (many patients do not want to wait weeks). Central Ohio Urology Group treats the overwhelming majority of stones — including very large burdens once considered “percutaneous only” — with ureteroscopy in our ambulatory surgery centers, reserving PCNL for the largest stones.

Procedure

our practice role

Ureteroscopy (URS) with laser lithotripsy

Our workhorse for ureteral and renal stones — including massive stones. Done in the ASC with best-in-class thulium fiber lasers, Dornier single-use digital scopes, and direct-in-line vacuum aspiration to evacuate fragments (superior clearance, lower intrarenal pressure). All patients are stented afterward.

Shock wave lithotripsy (SWL)

Non-invasive option for smaller stones in favorable locations; lower stone-free rate for hard/large stones. Poor for lower-pole stones, obesity, and dense stones (high Hounsfield units); contraindicated in pregnancy, uncorrected coagulopathy, and untreated infection.

Percutaneous nephrolithotomy (PCNL)

Reserved for the largest stones — generally > 4 cm — and complex/staghorn burdens; highest single-session clearance for those cases. The added risk of PCNL comes from the ACCESS TRACT — the working channel we create from the skin, through the flank muscles, into the kidney's collecting system (see below).

Stent or nephrostomy (decompression)

Temporizing for obstruction/infection before definitive treatment.

What “the tract” means in PCNL — and why it is the risk

  • The tract is the access channel. Unlike ureteroscopy, which reaches the stone through the body's own plumbing (urethra → bladder → ureter → kidney), PCNL requires us to make a NEW route: a needle is passed through the skin of the flank, through the muscle, through the kidney's parenchyma, and into a calyx of the collecting system. That channel is then dilated to about 24–30 Fr — roughly the width of a pen — so a rigid nephroscope can pass through it to break up and remove the stone. That channel is the tract.

  • Why it is dangerous: you are drilling through a highly vascular organ, and the neighbors are unforgiving. The complications all flow from creating it: BLEEDING (the kidney receives ~20% of cardiac output; the tract can injure a segmental artery and cause significant hemorrhage, an arteriovenous fistula, or a pseudoaneurysm — occasionally requiring angioembolization). INJURY TO ADJACENT STRUCTURES: if the access is placed above the 12th rib (a “supracostal” puncture, sometimes needed to reach an upper-pole stone), it can traverse the PLEURA and cause a hydrothorax or pneumothorax; a poorly placed tract can also injure the COLON, liver, or spleen. URINE LEAK from the tract, and INFECTION/SEPSIS from irrigating a stone-bearing, often colonized collecting system under pressure.

  • Afterward: a nephrostomy tube is usually left in the tract to drain the kidney and tamponade bleeding, and it is removed once drainage is clear. Post-op flank pain, some hematuria, and drainage around the tube are expected.

  • The bottom line for counseling: PCNL is more invasive than ureteroscopy precisely BECAUSE of the tract. That is the trade we make for the ability to clear a very large stone burden in one session — and it is exactly why we reserve it for stones over ~4 cm and clear everything else ureteroscopically.

our practice stone philosophy

  • ASC-based, incision-free treatment of massive stones: modern thulium-laser dusting plus vacuum aspiration and premium single-use digital ureteroscopes let us clear very large stones ureteroscopically in an outpatient surgery center — so PCNL is reserved for stones over ~4 cm.

  • All patients are stented after URS: our standard is to leave a ureteral stent following every ureteroscopy to protect the ureter, ensure drainage, and reduce post-op obstruction/pain.

  • The exception — the infected, obstructed stone: this is a HOSPITAL case, not an ASC case. That patient needs emergent decompression plus inpatient sepsis care (and possibly an ICU bed), and our ASCs are same-day-discharge facilities. Drain them at the hospital, control the infection, and bring them back to the ASC weeks later for definitive stone treatment (Chapter 2).

Stent counseling and stent-colic management

  • Ureteral stents commonly cause flank discomfort with voiding (reflux up the stent), urgency/frequency, and hematuria — this is expected, not failure. Warn the patient BEFORE surgery or they will think something went wrong.

  • Treat stent colic/symptoms with a urinary analgesic — phenazopyridine (Pyridium) or Uro-MP — plus mirabegron, which together relieve the bladder spasm and dysuria better than anything else; this is our go-to for the symptomatic stent.

  • For pain, use acetaminophen (Tylenol), suzetrigine (Journavx), and ketorolac IM in the office if renal function allows. Opioids are almost always avoided.

  • Ask about the last bowel movement. Patients with stents are often constipated from narcotics given in the emergency department or perioperatively, and constipation can amplify stent colic. Treat the bowel regimen rather than assuming the answer is more narcotic medication. Persistent or worsening pain still requires reassessment for obstruction, infection, impaired drainage, or stent migration.

  • Emphasize the removal date. A forgotten/retained stent can encrust, obstruct, and become a serious problem — track it. This is a classic, entirely preventable disaster.

7.4 Prevention and the metabolic work-up

Prevention is where most practices fail their stone patients. A recurrent stone former who never gets a 24-hour urine will simply be back.

Stone type

Key features

Targeted prevention

Calcium oxalate (~70–80%)

Most common; radio-opaque; forms in any pH

Fluids; adequate dietary calcium; limit oxalate and sodium; thiazide for hypercalciuria; potassium citrate for hypocitraturia; treat primary hyperparathyroidism if present

Calcium phosphate

Alkaline urine; associated with distal RTA and hyperparathyroidism

Address the underlying cause; careful with alkalinizing agents (they can worsen it)

Uric acid (~5–10%)

RADIOLUCENT on plain film (visible on CT); forms in ACIDIC urine (pH < 5.5); associated with gout, obesity, diabetes, and metabolic syndrome

Urinary alkalinization with potassium citrate to pH 6.0–6.5 — this can actually DISSOLVE the stone, which no other stone type does. Reduce purine intake; allopurinol if hyperuricosuric

Struvite (infection)

Magnesium ammonium phosphate; associated with UREASE-producing organisms (Proteus, Klebsiella, Ureaplasma); often forms staghorn calculi

Requires COMPLETE surgical clearance — any residual fragment harbors bacteria and regrows the stone — plus infection control. Do not leave fragments behind

Cystine (~1%)

Genetic (autosomal recessive cystinuria); recurrent from childhood; hexagonal crystals

High fluid intake (goal > 3–4 L/day), urinary alkalinization, and thiol-binding agents (tiopronin); refer for genetic counseling

Clinical Pathway

Click any node to expand

Stone disease is common, recurrent (roughly 50% recurrence within 5–10 years without prevention), and often exquisitely painful. Manage the acute episode, decide who needs intervention, treat definitively, and then actually set up prevention so patients do not keep coming back.

Diagnose the stone, screen immediately for the one presentation that cannot wait, then manage pain and passage.

Acute renal colicDiagnose the stone, screen immediately for the one presentation that cannot wait, then manage pain and passage. STEP 1 · PRESENTATIONSudden colicky flank pain in apatient who cannot sit stillWaxes and wanes; radiates to the groin,labia, or testis as the stone moves… STEP 2 · SCREEN FIRSTTIME-CRITICALFever plus an obstructing stone =emergent decompressionObstructive pyelonephritis / urosepsis.Antibiotics alone will not save this… STEP 3 · IMAGINGOrder a non-contrast CT of theabdomen/pelvisThe standard study — it answers everyquestion that drives management. STEP 4 · LABSSend UA, urine culture, CBC,creatinineHematuria is present in ~85% — itsABSENCE does not exclude a stone. STEP 5 · ANALGESIAUse Tylenol, Journavx, andketorolacOpioids are almost always avoided. STEP 6 · METUse tamsulosin 0.4 mg daily forany ureteral stone the patientwants to passOffer medical expulsive therapy wheneverthe patient chooses a trial of passage. STEP 7 · SET EXPECTATIONSSet passage expectations by stonesizeStones under 6 mm often pass; stones 8mm and larger typically require… STEP 8 · CAPTURE ITHydration and a strainer — sendevery captured stoneThe cheapest, most valuable test instone disease, and it is skipped…

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The discriminator

The patient is classically restless and cannot find a comfortable position — a useful discriminator from peritonitis, where patients lie still.

Also expect

  • Nausea and vomiting are common — shared celiac plexus innervation
  • A stone at the ureterovesical junction produces urgency and frequency that mimics a UTI
Ch 7.1 — presentation
Time-critical

Act now

  • Emergent decompression — stent or nephrostomy — plus antibiotics (Chapter 2)
  • Antibiotics alone will NOT save this patient

Also escalate for

  • Acute kidney injury
  • Bilateral obstruction
  • Obstruction of a solitary or transplanted kidney
  • Intractable pain or vomiting

Never miss it

The patient who looks "not that sick" with a fever and an obstructing stone can be in septic shock in three hours. Do not send them home.

Ch 7.1 — the stone emergency

What the CT tells you

  • Stone size
  • Location
  • Density in Hounsfield units — predicts fragility
  • Skin-to-stone distance
  • Degree of hydronephrosis

When to use something else

  • Ultrasound (radiation-sparing) — preferred in pregnancy, reasonable for younger patients and for follow-up
  • Plain KUB — useful only for tracking a known radio-opaque stone; uric acid stones are radiolucent
Ch 7.1 — diagnosis

Orders

  • Urinalysis
  • Urine culture
  • CBC
  • Creatinine
  • Calcium — and consider PTH later if hypercalcemic

Pitfall

  • A negative urinalysis does not rule out a stone — hematuria is present in only ~85%
Ch 7.1 — labs

Dosing

  • Acetaminophen (Tylenol)
  • Suzetrigine (Journavx) — oral NaV1.8 sodium-channel inhibitor
  • Ketorolac 15–30 mg IM in the office — if renal function allows

Why NSAIDs

They reduce ureteral wall edema and prostaglandin-mediated pain.

Our pain strategy

  • Use Tylenol, Journavx, and ketorolac
  • Opioids are almost always avoided
  • Antiemetics for nausea

Do not miss opioid-related constipation

  • Ask when the patient last had a bowel movement—many received narcotics in the emergency department
  • Stool burden can amplify renal colic
  • Restoring bowel function may help more than giving additional narcotics
  • Persistent or worsening pain still requires reassessment for infected obstruction or impaired drainage
Ch 7.2 — analgesia

Dosing

  • Tamsulosin 0.4 mg daily

Who gets MET

  • Use for any ureteral stone that the patient wants to try to pass
  • Tamsulosin relaxes ureteral smooth muscle and can aid stone passage
Ch 7.2 — MET

Spontaneous passage

  • < 6 mm — often pass spontaneously
  • ≥ 8 mm — typically require intervention
  • Distal stones pass more readily than proximal stones

Trial of passage

Give a reasonable trial of passage (up to ~4–6 weeks) ONLY if the patient is comfortable, not infected, and has normal renal function.

Ch 7.2 — expectations

Instruction to the patient

  • Strain all urine to capture the stone
  • Send EVERY captured stone for composition analysis
Ch 7.2 — hydration and a strainer

Central Ohio Urology Group treats the overwhelming majority of stones — including very large burdens once considered "percutaneous only" — with ureteroscopy in our ambulatory surgery centers.

Intervention — our practice approachCentral Ohio Urology Group treats the overwhelming majority of stones — including very large burdens once considered "percutaneous only" — with ureteroscopy in our ambulatory surgery centers. STEP 1 · INDICATIONDecide whether this stone needsinterventionWaiting is not free — many patients donot want to wait weeks. STEP 2 · THE EXCEPTIONTIME-CRITICALThe infected, obstructed stone isa HOSPITAL case, not an ASC caseOur ASCs are same-day-dischargefacilities. This patient may need an IC… WHICH PROCEDURE? WORKHORSELOCAL POLICYUreteroscopy with laserlithotripsy in the ASCOur workhorse in Ohio. Donein the Columbus ASC. NON-INVASIVEShock wave lithotripsyfor smaller favorablestonesLower stone-free rate forhard or large stones. LARGEST BURDENSPCNL — reserved forstones generally over 4cmComplex and staghornburdens; highest… TEMPORIZINGTIME-CRITICALStent or nephrostomy todecompressFor obstruction/infectionbefore definitive… COUNSELINGExplain what "the tract" is andwhy it carries the riskPCNL requires a NEW route rather thanthe body's own plumbing. PRE-OPLOCAL POLICYWarn the patient about stentsymptoms BEFORE surgeryExpected, not failure — but only if yousaid it first. POST-OPLOCAL POLICYTreat stent colic with a urinaryanalgesic plus mirabegronThis is our go-to for the symptomaticstent. DO NOT FORGETTIME-CRITICALTrack the stent removal dateA classic, entirely preventabledisaster. OHIO · LOCAL STEPLOCAL POLICYLog the stent in the Ohio stentregistryTODO — replace with this market's actualtracking process.

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Intervene for

  • Stones unlikely to pass
  • Refractory pain
  • Obstruction with infection — emergent
  • AKI
  • A solitary kidney
  • Patient preference
Ch 7.3
Time-critical

Our rule

That patient needs emergent decompression plus inpatient sepsis care (and possibly an ICU bed). Drain them at the hospital, control the infection, and bring them back to the ASC weeks later for definitive stone treatment (Chapter 2).

Ch 7.3 — our practice stone philosophy

Which procedure?

Local policy

What we use

  • Best-in-class thulium fiber lasers
  • Dornier single-use digital scopes
  • Direct-in-line vacuum aspiration to evacuate fragments — superior clearance, lower intrarenal pressure

Our standard

  • All patients are stented afterward — to protect the ureter, ensure drainage, and reduce post-op obstruction/pain

Ohio specifics

  • Columbus ASC — TODO confirm scheduling contact and block days
  • TODO — stent removal pathway and who owns the tickler in this market
Ch 7.3 — procedures

Poor choice for

  • Lower-pole stones
  • Obesity
  • Dense stones — high Hounsfield units

Contraindicated in

  • Pregnancy
  • Uncorrected coagulopathy
  • Untreated infection
Ch 7.3 — procedures

Where the risk lives

The added risk of PCNL comes from the ACCESS TRACT — the working channel we create from the skin, through the flank muscles, into the kidney's collecting system.

Ch 7.3 — procedures
Time-critical

Role

Temporizing for obstruction/infection before definitive treatment.

Ch 7.3 — procedures

What the tract is

Unlike ureteroscopy, which reaches the stone through the body's own plumbing (urethra → bladder → ureter → kidney), PCNL requires us to make a new route: a needle is passed through the skin of the flank, through the muscle, through the kidney's parenchyma, and into a calyx. That channel is dilated to about 24–30 Fr — roughly the width of a pen — so a rigid nephroscope can pass through it.

Why it is dangerous

  • Bleeding — the kidney receives ~20% of cardiac output; the tract can injure a segmental artery and cause significant hemorrhage, an AV fistula, or a pseudoaneurysm, occasionally requiring angioembolization
  • Injury to adjacent structures — a supracostal puncture above the 12th rib can traverse the PLEURA and cause hydrothorax or pneumothorax; a poorly placed tract can injure the COLON, liver, or spleen
  • Urine leak from the tract
  • Infection/sepsis from irrigating a stone-bearing, often colonized collecting system under pressure

Afterward

  • A nephrostomy tube is usually left in the tract to drain the kidney and tamponade bleeding; removed once drainage is clear
  • Post-op flank pain, some hematuria, and drainage around the tube are expected

The bottom line

PCNL is more invasive than ureteroscopy precisely BECAUSE of the tract. That is the trade we make to clear a very large stone burden in one session — and it is exactly why we reserve it for stones over ~4 cm and clear everything else ureteroscopically.

Ch 7.3 — what "the tract" means in PCNL
Local policy

What to warn about

  • Flank discomfort with voiding — reflux up the stent
  • Urgency and frequency
  • Hematuria

Pitfall

Warn the patient BEFORE surgery or they will think something went wrong.

Ch 7.3 — stent counseling
Local policy

Our regimen

  • A urinary analgesic — phenazopyridine (Pyridium) or Uro-MP — plus mirabegron
  • Together they relieve the bladder spasm and dysuria better than anything else

Pain control

  • Use acetaminophen (Tylenol), suzetrigine (Journavx), and ketorolac IM in the office if renal function allows
  • Opioids are almost always avoided

Check the bowels

  • Ask when the patient last had a bowel movement—narcotics from the emergency department or perioperative period commonly cause constipation
  • Constipation can amplify stent colic; restoring bowel function may help more than additional narcotics
  • Reassess persistent or worsening pain for obstruction, infection, impaired drainage, or stent migration
Ch 7.3 — stent-colic management
Time-critical

Why

A forgotten/retained stent can encrust, obstruct, and become a serious problem — track it. Emphasize the removal date with the patient.

Ch 7.3 — stent counseling
Local policy

Why this exists

An example of a step that exists in one market only. Delete or rewrite it.

Our process

  • TODO — who logs it
  • TODO — where it is logged
  • TODO — who audits it
Ohio local policy

Prevention is where most practices fail their stone patients. A recurrent stone former who never gets a 24-hour urine will simply be back.

Prevention & metabolic work-upPrevention is where most practices fail their stone patients. A recurrent stone former who never gets a 24-hour urine will simply be back. STEP 1 · THE ONE TESTSend the captured stone forcomposition analysisIt directs everything downstream. STEP 2 · UNIVERSAL ADVICEGive every stone former the samefour dietary rulesApplies regardless of stone type. STEP 3 · METABOLIC PANELOrder a 24-hour urine metabolicpanel for the right patientsVolume, calcium, oxalate, citrate, uricacid, sodium, pH, creatinine. TARGETED PREVENTION BY STONE TYPE ~70–80%Calcium oxalate —thiazide and potassiumcitrate as indicatedMost common; radio-opaque;forms in any pH. ALKALINE URINECalcium phosphate —find and fix theunderlying causeAssociated with distal RTAand hyperparathyroidism. ~5–10%Uric acid — alkalinizeto pH 6.0–6.5 anddissolve itThe only stone type you canactually dissolve. INFECTION STONEStruvite — clear itcompletely or itregrowsMagnesium ammoniumphosphate; urease-producin… THE RARE ONECystine — high fluids, alkalinize,and refer for genetics~1% of stones; autosomal recessivecystinuria, recurrent from childhood. THE POINTBook the prevention visit beforethey leaveRoughly 50% recur within 5–10 yearswithout prevention.

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Why

Send every captured stone for composition analysis. It directs everything downstream — and it is the cheapest, most valuable test in stone disease.

Ch 7.4

The rules

  • Fluid — enough to produce ~2.5 L of urine per day (usually ~3 L intake)
  • Sodium — moderate, < 2,300 mg/day; high sodium drives calcium into the urine
  • Calcium — NORMAL dietary calcium 1,000–1,200 mg/day
  • Protein — moderate animal protein
  • Oxalate — limit oxalate-rich foods (spinach, nuts, chocolate, tea, beets) for calcium-oxalate formers

The counterintuitive one

Do NOT restrict calcium: dietary calcium binds oxalate in the gut, and restricting it paradoxically INCREASES stone risk.

Ch 7.4 — universal advice

Warranted for

  • Recurrent stone formers
  • High-risk stone formers
  • Pediatric patients
  • Single-kidney stone formers
  • Anyone motivated to prevent recurrence

Close the loop

  • Repeat it after any intervention to confirm the change worked
Ch 7.4 — metabolic work-up

Targeted prevention by stone type

Targeted prevention

  • Fluids; adequate dietary calcium; limit oxalate and sodium
  • Thiazide for hypercalciuria
  • Potassium citrate for hypocitraturia
  • Treat primary hyperparathyroidism if present
Ch 7.4 — stone types

Caution

  • Be careful with alkalinizing agents — they can worsen calcium phosphate stones
Ch 7.4 — stone types

Treatment

  • Urinary alkalinization with potassium citrate to pH 6.0–6.5 — this can actually DISSOLVE the stone
  • Reduce purine intake
  • Allopurinol if hyperuricosuric

Recognize it

  • RADIOLUCENT on plain film, visible on CT
  • Forms in ACIDIC urine, pH < 5.5
  • Associated with gout, obesity, diabetes, metabolic syndrome
Ch 7.4 — stone types

Requirement

  • Requires COMPLETE surgical clearance — any residual fragment harbors bacteria and regrows the stone
  • Plus infection control
  • Do not leave fragments behind
Ch 7.4 — stone types

Management

  • High fluid intake — goal > 3–4 L/day
  • Urinary alkalinization
  • Thiol-binding agents — tiopronin
  • Refer for genetic counseling

Recognize it

  • Hexagonal crystals on urinalysis
Ch 7.4 — stone types

Pitfall

Prevention is where most practices fail their stone patients. A recurrent stone former who never gets a 24-hour urine will simply be back.

Ch 7.4

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