7: Congenital anomalies of the upper urinary tract: UPJ obstruction, duplication anomalies, ectopic ureter, ureterocele, and ureteral anomalies Flashcards

Question

What is the LM ureter more prone to in complete ureteral duplication? a. Distal obstruction b. Vesicoureteral reflux c. Ectopic ureteral insertion d. Ureterocele

Answer 1

b. Vesicoureteral reflux. Explanation: The LM ureter is more prone to vesicoureteral reflux via a shortened intramural tunnel length.

Answer 2

a. Distal obstruction. Explanation: The UM ureter is more prone to distal obstruction and may be associated with a ureterocele or ectopic ureteral insertion.

Answer 3

In the context of renal embryology, a ureteral bud is a small outgrowth from the mesonephric duct that gives rise to the ureter and renal collecting system. The ureteral bud interacts with the metanephric mesenchyme to induce the formation of the kidney.

Answer 4

In anatomy and biology, caudal means situated towards or relating to the tail or posterior end of the body. It is the opposite of "cranial," which means towards the head or anterior end of the body. In the context of renal embryology, "caudal" is often used to describe a position lower in the body or towards the back, as opposed to "cephalad," which describes a position higher in the body or towards the front.

Answer 5

b. COU alters the growth and differentiation of the developing kidney, while postnatal acquired obstruction does not. Explanation: Congenital obstructive uropathy (COU) is distinct from postnatal acquired obstruction in that it alters the growth and differentiation of the developing kidney.

Answer 6

c. Fibrosis and altered morphogenesis. Explanation: Key pathological patterns associated with COU include fibrosis and altered morphogenesis, which can ultimately lead to dysplasia in severe cases.

Answer 7

c. No, because altered function and pathophysiological processes can continue. Explanation: Postnatal correction of obstruction does not usually permit normalization but may limit progression. However, progression may continue because of altered function and ongoing pathophysiological processes.

Answer 8

b. No, they may appear normal on imaging even with significant histologic abnormalities. Explanation: Biopsy studies have shown that even with normal uptake on nuclear imaging, affected kidneys may have significant histologic abnormalities.

Answer 9

c. They are associated with later progression to renal insufficiency. Explanation: It has been shown that early insults to normal kidney development are associated with later progression to renal insufficiency.

Answer 10

c. Ureteropelvic junction obstruction (UPJO) Explanation: Ureteropelvic junction is the most common form of pediatric upper urinary tract obstruction.

Answer 11

: c. Both prenatal detection of hydronephrosis and symptomatic presentation of abdominal or flank pain. Explanation: The clinical presentation of UPJ obstruction is most commonly through prenatal detection of hydronephrosis, but it can also present with symptomatic presentation of abdominal or flank pain.

Answer 12

c. An episode of colicky flank pain with nausea and vomiting. Explanation: Abrupt onset of severe pain, frequently with nausea and vomiting that is colicky in nature, is the typical pattern of Deitl's crisis, which can be seen in UPJ obstruction.

Answer 13

d. Dismembered pyeloplasty. Explanation: The gold standard for correcting UPJ obstruction is a dismembered pyeloplasty.

Answer 14

a. Markedly increased hydronephrosis, > 10% decrease in relative uptake on renography, and symptoms such as pain or UTI. Explanation: Clear indications for surgery in UPJ obstruction include markedly increased hydronephrosis, > 10% decrease in relative uptake on renography, and symptoms such as pain or UTI.

Answer 15

b. A developmental anomaly in the lower pole of the kidney. Explanation: Extrinsic UPJ obstruction is often caused by a lower pole vessel of the kidney that creates a kinking of the ureter.

Answer 16

a. Yes, in some cases. Explanation: Spontaneous resolution of UPJ obstruction is common in many infants.

Answer 17

c. May be due to either an intrinsic or extrinsic cause. Explanation: The underlying etiology of UPJ obstruction is variable and may be due to either an intrinsic or extrinsic cause.

Answer 18

c. Through prenatal detection of hydronephrosis. Clinical presentation of UPJ obstruction is most commonly through prenatal detection of hydronephrosis, which is typically seen on an anatomic screening ultrasound performed at 20 weeks' gestation. If hydronephrosis is detected, further monitoring of the dilation is warranted with serial ultrasonography. Option a is incorrect because imaging during an episode of Deitl's crisis may reveal increased dilation from a baseline study, but this is not the most common way that UPJ obstruction is diagnosed. Option b is incorrect because presenting with symptoms of gastroenterologic problems may lead to a missed diagnosis of UPJ obstruction. Option d is incorrect because although a diuretic renogram may be used to evaluate UPJ obstruction, it is not the most common way that it is diagnosed.

Answer 19

C. The relative function of the affected kidney compared with the contralateral is one of the key factors evaluated using diuretic renography for UPJ obstruction. This helps to assess the degree of obstruction and guide management decisions. The washout time following Lasix administration is also evaluated. The number of dilated renal calyces and the size of the dilation in the affected pelvis may be assessed using ultrasound or other imaging modalities, but they are not key factors evaluated using diuretic renography. The presence of lower pole vessel obstruction may be a cause of extrinsic obstruction, but it is not directly evaluated using diuretic renography.

Answer 20

c. Every 3 months. According to the given information, a practical observation plan for conservative management of UPJ obstruction would include follow-up ultrasonography every 3 months during the first year of life.

Answer 21

b. Markedly increased hydronephrosis, > 10% decrease in relative uptake on renography, and symptoms such as pain or UTI. According to the given information, clear indications for surgery in a patient with UPJ obstruction include markedly increased hydronephrosis, > 10% decrease in relative uptake on renography, and symptoms such as pain or UTI. Persistence of hydronephrosis with no improvement over time may also be an indication for intervention.

Answer 22

a) Diuretic renogram after 3 months is the recommended postoperative evaluation after a dismembered pyeloplasty. Explanation: Typical postoperative evaluation includes a renal ultrasound 4-8 weeks after surgery, and continued monitoring is reasonable. Some groups perform a diuretic renogram at 3 months, and if this drains well, discontinue further follow-up. However, ongoing monitoring of hydronephrosis for 2-5 years is prudent.

Answer 23

a) Urinary leakage and development of a urinoma are potential complications of surgical management for UPJ obstruction. Explanation: Other potential complications of surgical management for UPJ obstruction include postoperative infection, which is common, and persisting obstruction, which is uncommon and may require replacement of a ureteral stent, balloon dilation, or reoperative pyeloplasty.

Answer 24

C. A narrow, peristaltic segment of the intramural ureter causing a variable degree of upper tract obstruction. Explanation: UVJO, also referred to as primary obstructed megaureter, results from a narrow, aperistaltic segment of intramural ureter, causing a variable degree of upper tract obstruction.

Answer 25

: B. Hydroureter of > 7 mm, regardless of etiology. Explanation: The term “megaureter” is used to describe hydroureter of ≥ 7 mm, regardless of etiology.

Answer 26

C. Febrile UTI Explanation: Infants or children may present with febrile UTI, sepsis, pain, stones, or microscopic hematuria.

Answer 27

B. Observation Explanation: Even in the setting of delayed excretion on renogram, observation is the preferred management approach for children with UVJO who have no infections or functional loss.

Answer 28

D. All of the above Explanation: Indications for definitive reconstruction include recurrent or severe infection, ipsilateral function under 40%, and significant or sequential functional decline. Stone formation, pain, or progressive, unremitting dilation may also prompt surgery in some patients.

Answer 29

B. Ultrasonography and VCUG Explanation: Prenatally detected hydroureteronephrosis generally prompts ultrasonography and VCUG as initial studies.

Answer 30

A. Conservative management with observation and serial ultrasounds Explanation: Even in the setting of delayed excretion on renogram, observation is the preferred management approach for children with UVJO who have no infections or functional loss. Infants are typically placed on antibiotic prophylaxis given concern for UTI within a relatively static, dilated system. Serial ultrasounds are obtained frequently during year 1 and every 6–12 months thereafter. A renogram may be repeated less often to confirm functional stability and improved drainage.

Answer 31

B. Intravesical or extravesical approaches for excision of the narrow adynamic segment and ureteral reimplantation Explanation: UVJO is repaired via excision of the narrow adynamic segment and ureteral reimplantation. Intravesical or extravesical approaches may be utilized. Ureteral tailoring, either by plication or excisional tapering, is usually required. Endoscopic management with manual or balloon dilation of the UVJ followed by temporary ureteral stent placement has been described as a minimally invasive alternative to tapered ureteral reimplant.

Answer 32

B) A cystic dilation of the distal ureter within the bladder Explanation: A ureterocele is a cystic dilation of the distal ureter within the bladder, often associated with upper tract obstruction.

Answer 33

C) According to their location and configuration Explanation: Ureteroceles are classified according to their location and configuration.

Answer 34

D) During evaluation for prenatal hydronephrosis Explanation: Ureteroceles are often identified during evaluation for prenatal hydronephrosis or may present clinically with febrile UTI.

Answer 35

C) Renal bladder ultrasound and VCUG Explanation: Initial evaluation typically consists of renal bladder ultrasound and VCUG.

Answer 36

A) Preservation of functional renal parenchyma Explanation: Management goals include preservation of functional renal parenchyma (via correction of obstruction and prevention of VUR), elimination or prevention of infection, maintenance of continence, and minimization of procedural morbidity.

Answer 37

B) Prolapse of the ureterocele through the urethra as an interlabial mass Explanation: Infant girls occasionally present with an interlabial mass, representing prolapse of the ureterocele through the urethra.

Answer 38

C) Distortion of trigonal and urethral anatomy and affect the continence mechanism Explanation: Large ureteroceles can distort trigonal and urethral anatomy and affect the continence mechanism.

Answer 39

C) Bacteremia and sepsis Explanation: Infections may be severe, with bacteremia and sepsis, and are a potential complication of a ureterocele-associated UTI.

Answer 40

D) By their appearance on ultrasound Explanation: A ureterocele may be differentiated from an ectopic ureter based on ultrasound appearance.

Answer 41

C) A circular filling defect Explanation: On VCUG, a ureterocele appears as a circular filling defect, best appreciated during early filling.

Answer 42

A) Bladder diverticulum Explanation: During voiding, ureterocele eversion mimics the appearance of a bladder diverticulum and may indicate a weak trigonal floor.

Answer 43

B) To evaluate for obstruction and relative function of the associated renal unit Explanation: Nuclear scan can be used to evaluate for obstruction and relative function of the associated renal unit, though not reliable in the first weeks of life.

Answer 44

C) Serial ultrasounds and antibiotic prophylaxis Explanation: Infants with improving mild to moderate unilateral hydronephrosis and small intravesical ureteroceles are often managed conservatively. Infants are typically placed on antibiotic prophylaxis and followed with serial ultrasounds.

Answer 45

A) Because they are at higher risk for developing UTIs Explanation: Families are educated on the signs and symptoms of UTI in infants with ureteroceles because infections may be severe, with bacteremia and sepsis.

Answer 46

B) 6-12 weeks of age Explanation: Nuclear renogram at 6–12 weeks of age may be useful.

Answer 47

B) Absent or low-grade ipsilateral VUR Explanation: Factors associated with a more benign clinical course include absent or low-grade ipsilateral VUR and absent function of the associated renal unit (multicystic dysplastic kidney [MCDK], nonfunctioning UM).

Answer 48

B) Severe or worsening ipsilateral hydronephrosis Explanation: Indications for surgical intervention in ureteroceles include infection, severe or worsening ipsilateral hydronephrosis, and bilateral hydronephrosis (secondary to obstruction of bladder outlet or contralateral ureteral orifice).

Answer 49

B) Severe or worsening ipsilateral hydronephrosis Explanation: Indications for surgical intervention in ureteroceles include infection, severe or worsening ipsilateral hydronephrosis, and bilateral hydronephrosis (secondary to obstruction of bladder outlet or contralateral ureteral orifice).

Answer 50

C) Transurethral incision or puncture of the ureterocele Explanation: Decompression is accomplished via transurethral incision or puncture of the ureterocele.

Answer 51

B) Angled-tip hot wire and Collins knife Explanation: A cold knife, angled-tip hot wire, Bugbee, laser, or Collins knife is used to achieve a transverse full-thickness incision in the ureterocele.

Answer 52

D) Ipsilateral de novo reflux via the surgically created defect Explanation: The primary risk of endoscopic treatment is ipsilateral de novo reflux via the surgically created defect.

Answer 53

B) Between 1 and 2 years of age Explanation: In many cases, transurethral incision serves to alleviate obstruction until infants are old enough for definitive reconstruction, often planned between 1 and 2 years of age.

Answer 54

b. An abnormally cephalad ureteral budding from the mesonephric duct that inserts caudal to the normal orthotopic position on the trigone is known as an ectopic ureter.

Answer 55

d. Magnetic resonance urography (MRU) may be used when the location of ectopic insertion is uncertain, or the anatomy is complex. MRU can provide functional information but requires sedation in young children.

Answer 56

a. Continuous urinary leakage is a common presentation of an ectopic ureter in girls because insertion into the genital tract bypasses the external sphincter.

Answer 57

a. Ureteral reimplantation with or without tapering is the definitive management option for children with a single-system ectopic ureter and salvageable ipsilateral renal function.

Answer 58

c. Loop or end ureterostomy may be used as a temporizing diversion for infants with ectopic ureter requiring temporizing diversion. This provides decompression and functional assessment of the affected unit before definitive management.

Answer 59

c. An ectopic ureter inserts caudal to the normal orthotopic position on the trigone, resulting from an abnormally cephalad ureteral budding from the mesonephric duct.

Answer 60

c. Ectopic ureters and ureteroceles may be associated with a single system kidney or the UM of a duplex system.

Answer 61

c. Ectopic ureters most commonly insert into the bladder neck or proximal urethra but may also terminate in the genital tract.

Answer 62

b. Severe bladder and ureter dilation is a common finding on prenatal detection of ectopic ureter.

Answer 63

c. Infants and children with ectopic ureter may present with chronic low-grade fevers yet negative urine culture results, or with dramatic systemic infection.

Answer 64

a. Boys with ectopic ureter do not present with incontinence because the ectopic insertion is proximal to the external sphincter.

Answer 65

d. Boys with ectopic ureter may present with epididymo-orchitis at an unusually early age when the ectopic ureter inserts into Wolffian duct structures.

Answer 66

c. Perineal examination in girls with ectopic ureter may reveal a dilated Gartner's duct cyst in the vagina, and urine may be expressed from a vaginally inserting orifice.

Answer 67

c. Renal ultrasound (RUSD), VCUG, and nuclear scan are used for initial evaluation of ectopic ureter.

Answer 68

d. An ectopic ureter can be differentiated from a ureterocele on ultrasound by a relatively thicker partition between bladder and ureter and a lumen that extends well outside of the bladder lumen.

Answer 69

b. In a duplex system with ectopic UM ureter, LM reflux is common.

Answer 70

b. The more remote an ectopic ureteral insertion (i.e., vas deferens, ejaculatory duct, uterus), the higher the risk of dysplasia and reduced function.

Answer 71

The Gartner's duct is a vestigial structure in females that arises from the Wolffian duct system during fetal development. It is a remnant of the mesonephric duct, which in males forms the epididymis, vas deferens, and seminal vesicle. In females, the Gartner's duct is located on each side of the vagina and can vary in size and shape. It is typically small and not clinically significant, but in some cases, it can dilate and form a cyst, which may be detected during a perineal examination. In females with an ectopic ureter, the orifice of the ureter may insert into the Gartner's duct cyst, leading to continuous urinary leakage.

Answer 72

Vestigial refers to a trait or structure that has lost most or all of its original function through evolution. In other words, vestigial structures were once useful to an organism, but over time, they have become nonfunctional or have lost their original function. Examples of vestigial structures in humans include the appendix, which was once thought to play a role in digestion but is now believed to have no significant function, and the coccyx or tailbone, which was once used for balance and support in animals with tails but has lost its original function in humans.

Answer 73

a. For infants with ectopic ureter and associated lower moiety VUR, antibiotic prophylaxis is appropriate while awaiting definitive treatment.

Answer 74

c. In general, common sheath ureteral reimplantation is the foremost option for children with UM function and LM VUR because reflux in this setting is unlikely to resolve spontaneously.

Answer 75

C) Multicystic dysplastic kidney Explanation: Multicystic dysplastic kidney (MCDK) is the most common cause of renal cystic disease in infants and young children.

Answer 76

C) Prenatal ultrasound Explanation: MCDK is typically detected via prenatal ultrasound.

Answer 77

B) By a haphazard distribution of noncommunicating cysts without a larger central cyst Explanation: MCDK is radiographically characterized by a haphazard distribution of noncommunicating cysts without a larger central cyst.

Answer 78

C) Spontaneous involution is common. Explanation: The natural history of MCDK is benign with a high rate of spontaneous involution.

Answer 79

C) When MCDK causes mass effect with respiratory or gastrointestinal compromise, refractory hypertension, or spontaneous rupture or hemorrhage from trauma Explanation: Nephrectomy is indicated when MCDK causes mass effect with respiratory or gastrointestinal compromise, refractory hypertension, or spontaneous rupture or hemorrhage from trauma.

Answer 80

D) Juvenile nephronophthisis Explanation: Juvenile nephronophthisis (JN) is the most common genetic cause of end-stage renal disease in childhood and adolescence.

Answer 81

B) Small kidneys bilaterally with loss of corticomedullary differentiation and corticomedullary cysts Explanation: Patients with JN have small kidneys bilaterally with loss of corticomedullary differentiation and corticomedullary cysts, which may not appear until adolescence or adulthood.

Answer 82

Explanation: ARPKD typically presents in infancy or childhood, while ADPKD typically presents in the third or fourth decade of life.

Answer 83

A) Mutations in the PKHD1 gene Explanation: ARPKD results from mutations in the PKHD1 gene.

Answer 84

B) Management is supportive, with blood pressure control and sodium replacement in some cases. Dialysis and transplant are often required. Explanation: The management for both Juvenile nephronophthisis and medullary cystic kidney disease is supportive, with blood pressure control and sodium replacement in some cases. Dialysis and transplant are often required, and grafts are not susceptible to either disease process.

Answer 85

B) Multicystic dysplastic kidney Explanation: Multicystic dysplastic kidney (MCDK) is the second most common cause of an abdominal mass in newborns (severe hydronephrosis is the most common).

Answer 86

C) Medullary cystic kidney disease presents with hypertension and may develop gout during adolescence, while juvenile nephronophthisis is typically associated with normal blood pressure. Explanation: Medullary cystic kidney disease and juvenile nephronophthisis have nearly identical presentation, but patients with medullary cystic kidney disease have hypertension and may develop gout during adolescence, while juvenile nephronophthisis is typically associated with normal blood pressure.

Answer 87

D) Mutations in the PKD1 or PKD2 genes Explanation: Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in the PKD1 or PKD2 genes.

Answer 88

C) Blood pressure monitoring is necessary for all patients with renal cystic disease. Explanation: Blood pressure monitoring is an important aspect of the management of renal cystic disease, as patients may develop hypertension as a complication of the condition. This is true for all types of renal cystic disease.

Answer 89

C) Oligohydramnios and respiratory distress after delivery secondary to pulmonary hypoplasia Explanation: ARPKD in infants and children can result in oligohydramnios and respiratory distress after delivery secondary to pulmonary hypoplasia.

Answer 90

A) Increased echogenicity because of microcysts Explanation: The radiographic appearance of kidneys in ARPKD is increased echogenicity because of microcysts.

Answer 91

B) Polyuria, polydipsia, and small stature Explanation: Patients with juvenile nephronophthisis or medullary cystic kidney disease typically present with polyuria, polydipsia, and small stature.

Answer 92

A) A concentration defect Explanation: Polyuria in patients with juvenile nephronophthisis is caused by a concentration defect.

Answer 93

A calyceal diverticulum is a cystic cavity lined by transitional epithelium that communicates with a calyx or renal pelvis through a narrow isthmus.

Answer 94

Small calyceal diverticula are usually asymptomatic, but they may present clinically with pain, infection, milk of calcium, or stone formation.

Answer 95

Ultrasound can diagnose a calyceal diverticulum by demonstrating a fluid-filled area positioned more centrally than a simple cortical cyst.

Answer 96

Computed tomography or magnetic resonance urogram may show pooling of contrast in a calyceal diverticulum.

Answer 97

Surgical intervention for a calyceal diverticulum is indicated in patients who have febrile UTI, pain, or stone formation.

Answer 98

The surgical approach for a calyceal diverticulum is determined by the diverticular position and orientation. Posterior diverticula may be approached percutaneously, anteriorly located diverticula may be approached laparoscopically or robotically, and superiorly located diverticula may be approached ureteroscopically with methylene blue localization, diverticular neck dilation, and endoscopic stone extraction.

Answer 99

Asymptomatic patients with a calyceal diverticulum do not require treatment.