Overview
Definition:
Laparoscopic pyeloplasty is a minimally invasive surgical procedure to correct ureteropelvic junction (UPJ) obstruction, a congenital anomaly where the renal pelvis is obstructed from draining into the ureter
It involves excising the obstructed segment and performing a new, tension-free anastomosis between the renal pelvis and the ureter
This approach offers reduced pain, shorter hospital stays, and faster recovery compared to open surgery.
Epidemiology:
UPJ obstruction is the most common cause of congenital hydronephrosis, affecting approximately 1 in 500 to 1 in 1500 live births
It is more common in males and in the left kidney
While often diagnosed antenatally, it can present in infancy, childhood, or even adulthood.
Clinical Significance:
Untreated UPJ obstruction can lead to progressive renal damage, pain, recurrent infections, stone formation, and hypertension
Early diagnosis and surgical correction are crucial to preserve renal function and prevent long-term complications
Laparoscopic pyeloplasty has become the gold standard treatment due to its efficacy and favorable outcomes.
Clinical Presentation
Symptoms:
In infants: Failure to thrive
Irritability
Palpable abdominal mass
In children and adults: Intermittent flank or abdominal pain, often postprandial or with increased fluid intake
Recurrent urinary tract infections (UTIs), often with fever
Nausea and vomiting
Hematuria (gross or microscopic).
Signs:
Physical examination may reveal a palpable abdominal mass (enlarged kidney) in severe cases
Tenderness in the flank or abdomen
Signs of infection such as fever and tachycardia
Normal vital signs are expected in asymptomatic patients.
Diagnostic Criteria:
Diagnosis is typically based on a combination of imaging studies demonstrating hydronephrosis, a dilated renal pelvis, and a narrowed UPJ, along with evidence of obstructed drainage
Clinical suspicion is raised by characteristic symptoms and antenatal hydronephrosis detected on ultrasound.
Diagnostic Approach
History Taking:
Detailed history of symptoms including onset, duration, severity, and triggers
Past medical history, especially of UTIs, kidney stones, or abdominal surgeries
Family history of congenital anomalies
For infants, inquire about feeding, weight gain, and irritability.
Physical Examination:
General examination for signs of distress or dehydration
Abdominal palpation for masses or tenderness
Percussion of the flanks
Genitourinary examination to rule out other causes of obstruction.
Investigations:
Renal ultrasonography (initial imaging modality, shows hydronephrosis, pelvicalyceal dilatation)
Intravenous pyelography (IVP) or CT urography (CTU) (demonstrates the anatomy and degree of obstruction)
Renal scintigraphy (Diuretic renogram or MAG3 scan) (assesses differential renal function and drainage, crucial for confirming obstruction and guiding management)
Urinalysis (for infection or hematuria)
Serum creatinine (to assess renal function).
Differential Diagnosis:
Other causes of hydronephrosis and flank pain: primary vesicoureteral reflux (VUR), ureteral stones, external compression (e.g., tumors, cysts), posterior urethral valves (in males), ureterocele, and ureteral strictures due to other causes.
Management
Initial Management:
Asymptomatic patients with mild hydronephrosis and good differential function may be managed with observation and serial ultrasounds
Symptomatic patients or those with significant obstruction and decreased renal function require surgical intervention
If infected, antibiotics are administered promptly.
Surgical Management:
Laparoscopic pyeloplasty is the preferred surgical approach
Indications include symptomatic obstruction, significant hydronephrosis with poor differential function (<40% on MAG3 scan), stone formation in the dilated system, or recurrent UTIs secondary to obstruction
The standard technique involves dismembering the UPJ, excising the narrowed segment, spatulating the ureter, and performing a dismembered, end-to-end, or Y-V plasty anastomosis, often with a transanastomotic stent
Open pyeloplasty is reserved for cases where laparoscopy is not feasible or has failed.
Postoperative Care:
Pain management with analgesics
Intravenous fluids until oral intake is adequate
Monitoring urine output and vital signs
Transanastomotic stent removal typically after 1-2 weeks
Early ambulation is encouraged
Follow-up imaging (ultrasound or renogram) is performed at 1, 3, and 6 months postoperatively to assess drainage and renal function.
Complications
Early Complications:
Bleeding
Infection (wound infection, UTI)
Urine leak (urinoma)
Ileus
Injury to adjacent organs
Clots in the renal pelvis or ureter
Stent migration or occlusion.
Late Complications:
Recurrence of UPJ obstruction (due to stricture at anastomosis or residual abnormal segment)
Persistent or recurrent pain
Stone formation
Chronic kidney disease
Hypertension.
Prevention Strategies:
Meticulous surgical technique, adequate spatulation of the ureter, tension-free anastomosis, appropriate stenting, and careful postoperative monitoring
Judicious patient selection for surgery
Prompt management of any signs of infection or urine leak.
Prognosis
Factors Affecting Prognosis:
Preoperative differential renal function
Degree of hydronephrosis
Quality of surgical repair
Absence of complications
Patient age and comorbidities.
Outcomes:
Successful outcomes are generally excellent, with reported success rates of 90-98% for laparoscopic pyeloplasty
Relief of obstruction leads to improved drainage, reduced pain, and resolution of infections
Long-term preservation of renal function is expected in most cases.
Follow Up:
Regular follow-up with renal ultrasonography and/or diuretic renography is essential to monitor for recurrent obstruction or functional decline
Typically, follow-up continues for at least 1-2 years postoperatively, with longer monitoring if any concerns arise.
Key Points
Exam Focus:
Laparoscopic pyeloplasty is the gold standard for symptomatic UPJ obstruction
Key imaging modalities are ultrasound, CTU, and MAG3 renogram
MAG3 scan is vital for assessing differential function and drainage
Success rates are high
Complications include recurrence, infection, and urine leak.
Clinical Pearls:
Always consider UPJ obstruction in a child with unexplained flank pain or recurrent UTIs
A MAG3 scan is critical to confirm obstruction and assess renal function before intervention
Ensure adequate spatulation of the ureter to prevent anastomotic stenosis
Early stenting is often used to promote healing.
Common Mistakes:
Over-reliance on ultrasound alone without functional assessment (MAG3 scan)
Undertaking surgery in asymptomatic patients with good function and no evidence of obstruction
Inadequate spatulation of the ureter, leading to recurrent stenosis
Premature removal of the transanastomotic stent.