What are the indications and required pre‑operative investigations for the various nephrology surgical procedures?

Nephrology Surgery: Indications and Pre-operative Investigations

The major nephrology surgical procedures include nephrectomy (partial or radical) for renal cell carcinoma, donor nephrectomy for transplantation, and stone removal procedures, each with distinct indications and investigation requirements based on 2022-2026 guidelines.

Renal Cell Carcinoma Surgery

Indications

• Partial nephrectomy (PN): Strongly recommended for all T1 tumors (≤7 cm) 1
• Radical nephrectomy (RN): Indicated for T2 tumors not amenable to PN, or when minimally invasive PN would compromise outcomes 1
• Thermal ablation: Reserved for frail/comorbid patients with small renal masses, not routinely offered for tumors >3 cm 1

Pre-operative Investigations

Imaging (Strong recommendations):

• Multiphase contrast-enhanced CT of abdomen and chest for diagnosis and staging 1
• Chest CT may be omitted in cT1a disease due to low metastasis risk 1
• MRI to evaluate venous involvement, reduce radiation, or avoid CT contrast 1
• Pre-operative CT is mandatory before PCNL 1

Biopsy requirements:

• Perform renal tumor biopsy before ablative therapy (Strong) 1
• Use core biopsy technique, not fine needle aspiration (Strong) 1
• Use coaxial technique (Strong) 1
• Do NOT biopsy cystic masses unless significant solid component visible (Strong) 1

Additional staging:

• Brain CT/MRI for metastatic disease when systemic therapy or cytoreductive nephrectomy considered 1
• Do NOT routinely use bone scan or PET-CT for RCC staging 1

Living Donor Nephrectomy

Indications

Donor candidates must undergo comprehensive evaluation, but specific surgical indications include:

Pre-operative Investigations (All required)

Imaging:

• Renal imaging (CT angiography preferred) to assess anatomy before nephrectomy 2
• Must identify number of renal arteries, venous anatomy, and any abnormalities 2

Exclusion criteria:

• Atherosclerotic renal artery disease or fibromuscular dysplasia involving both renal artery orifices 2
• Procurement of kidneys with ≥3 arteries only by experienced surgeons 2

Surgical approach selection:

• Left kidney preferred for laparoscopic approach due to longer venous pedicle 2
• Right kidney procurement requires adequate surgeon training and experience 2

Pre-transplant Native Nephrectomy

Indications 3, 4, 5

• Recurrent/chronic pyelonephritis with persistent urinary tract infection
• Vesicoureteral reflux with recurrent UTI
• Uncontrolled or malignant hypertension
• Polyuria >2.5 ml/kg/h
• Heavy proteinuria >40 mg/m²/h
• Chronic pyelonephritis or hydronephrosis with infection
• Renal calculi
• Structural urinary tract abnormalities predisposing to infection
• Goodpasture's disease or rapidly progressive glomerulonephritis

Pre-operative Investigations 5, 6

• Thorough nephrological work-up and patient preparation
• Serum electrolytes, creatinine, BUN
• Avoid potentially nephrotoxic drugs
• Minimize contrast agent exposure (risk of renal function deterioration)
• Dialysis 1 day preoperatively 5
• Central venous pressure monitoring capability
• Serial vital signs, weights, serum electrolytes monitoring planned

Critical perioperative management:

• Vigorous fluid replacement (average 5,890 cc before postoperative dialysis) 5
• Postoperative dialysis within 29 hours 5
• Avoid the outdated approach of minimal hydration

Kidney and Ureteral Stone Surgery

Indications by Stone Characteristics

Ureteral stones ≤10 mm distal:

• Medical expulsive therapy (MET) with alpha-blockers for ~30 days first-line (Strong) 7
• Surgical intervention if MET fails

Kidney stones requiring surgery:

• Symptomatic stones
• Obstructing stones
• Infection stones (require complete removal) 8
• Stones with growth on surveillance

Pre-operative Investigations

Imaging:

• Non-contrast abdominopelvic CT is most reliable for stone size, volume, location, number, density 7
• CT mandatory before PCNL to assess anatomy, stone-to-skin distance, infundibular angle 7, 9
• Cross-sectional imaging may be obtained for complex stones or anatomy 8

Laboratory:

• Serum electrolytes, creatinine, BUN if reduced renal function suspected 8
• Urine culture mandatory - do NOT proceed with surgery if untreated bacteriuria/funguria present (Clinical Principle) 7
• Culture-directed antimicrobial therapy required before surgery, even if asymptomatic 7

Stone analysis:

• Send stone material for analysis (Clinical Principle) 8
• Exception: documented similar composition on multiple recurrences

Kidney Trauma Surgery

Indications 10

• Hemodynamic instability despite resuscitation
• Associated injuries requiring laparotomy
• Failure of non-operative management or angioembolization
• Severe injury with main renal vein injury (angioembolization not indicated)

Pre-operative Investigations 10

• CT scan with intravenous contrast and delayed urographic phases for accurate injury classification
• Retrograde cystography for suspected bladder injuries (more sensitive than CT cystography)
• Retrograde urethrography for suspected urethral injuries
• Direct inspection during emergency laparotomy when feasible

Common Pitfalls to Avoid

1. Do NOT perform ipsilateral adrenalectomy without clinical evidence of invasion 1
2. Do NOT offer systematic lymph node dissection for organ-confined RCC 1
3. Do NOT use nontransfixing clips for renal artery ligation in donor nephrectomy - use suture ligature or anchor staples 2
4. Do NOT proceed with stone surgery without treating bacteriuria first 7
5. Do NOT underhydrate pre-transplant nephrectomy patients - vigorous fluid replacement is safe with prompt dialysis 5
6. Do NOT rely on intraoperative fluoroscopy alone for stone-free status - sensitivity only 24-50% compared to post-op CT 9