Lower Urinary Tract Obstruction

Posterior Urethral Valves: Practice Essentials, Pathophysiology, Etiology

Lower Urinary Tract Obstruction | Johns Hopkins Medicine

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  27. Nassr AA, Shazly SAM, Abdelmagied AM, Araujo Júnior E, Tonni G, Kilby MD, et al. Effectiveness of vesicoamniotic shunt in fetuses with congenital lower urinary tract obstruction: an updated systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2017 Jun. 49 (6):696-703. [Medline].

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  29. Horowitz M, Harel M, Combs A, Glassberg K. Surveillance cystoscopy in the management of posterior urethral valves. J Urol. 2009 Apr. 181 (4):172.

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  31. López Pereira P, Ortiz R, Espinosa L, Martínez Urrutia MJ, Lobato R, Alonso A, et al. Does bladder augmentation negatively affect renal transplant outcome in posterior urethral valve patients?. J Pediatr Urol. 2014 Oct. 10 (5):892-7. [Medline].

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Source: https://emedicine.medscape.com/article/1016086-overview

Lower Urinary Tract Obstruction

Lower Urinary Tract Obstruction | Johns Hopkins Medicine

Linkedin Pinterest Rare Pregnancy Complications

A lower urinary tract obstruction (LUTO) is a rare fetal condition that occurs when there is a blockage in the urinary tract of a developing fetus.

The urinary tract:

The urinary tract consists of the organs that produce and store urine:

As a fetus grows in the womb, urine made by the kidneys flows through the ureters into the bladder. Urine is stored in the bladder until it gets full. When the bladder is full, it pushes the urine the body through a tube called the urethra.

The kidneys and ureters are called the upper urinary tract and the bladder and urethra are called the lower urinary tract. LUTO occurs when the flow of urine is blocked from exiting the body at the level of the lower urinary tract.

 

When LUTO occurs, all parts of the urinary tract that lie above the obstruction may become swollen with urine that cannot drain. Over time this blockage can lead to permanent kidney damage.

When urine can no longer be drained, the fluid around the fetus (amniotic fluid) decreases. This can lead to lung damage because the fetus must move amniotic fluid in and the lungs in order for them to develop properly.

Therefore, LUTO can lead to damage in more than one organ system.

While some birth defects can be prevented through prenatal care, it's important to know what treatments may exist if your fetus is diagnosed with a birth defect.

Sometimes LUTO is caused by a problem with a fetus’s chromosomes or by a genetic disorder. If so, additional medical problems or organ abnormalities may be present.

Sometimes in male fetuses a fold of tissue from the bladder (posterior urethral valve) blocks the hole that allows drainage of the bladder into the urethra.

In other instances, parts of the urethra may be too narrow or completely blocked (urethral atresia).

LUTO without any other underlying conditions is called “isolated” LUTO. While ultrasounds and amniocentesis can help determine the cause of LUTO, testing after birth will give the most accurate analysis of a baby’s condition.

If a LUTO seems to be isolated, fetal surgical treatment may help decrease the amount of lung and kidney damage that can occur during pregnancy.

The goal of fetal treatment is to provide constant drainage of urine from the body into the amniotic fluid. This prevents urine buildup and helps to normalize amniotic fluid volume.

The type of treatment used depends on where in the urinary tract the blockage occurs. Types of treatments include:

  • Vesicocentesis: A needle is placed into the fetal bladder to remove the urine. Multiple procedures may be needed if urine repeatedly builds up in the bladder. One in ten fetuses may require only a single vesicocentesis to resolve LUTO.
  • Vesicoamniotic shunt: A small, plastic tube called a shunt is inserted into the bladder to allow the flow of urine from the bladder to the outside of the fetus. The shunt remains in the bladder until the baby is born.
  • Fetal cystoscopy: A small, surgical camera called a cystoscope can be inserted into the fetus’s urethra and bladder to remove any blockage in the flow of urine.

Not all attempts at fetal treatment are successful. Sometimes the position of the fetus makes it difficult to detect on ultrasound, making it impossible to perform a fetal therapy procedure. Even if a fetal treatment successfully decreases the amount of urine trapped in the baby, complications can still occur. The urine can build up again over time.

Fetal surgery does not completely eliminate the possibility of severe kidney or lung damage. Since fetal intervention involves risks to the fetus and to the mother, it is important to reserve these prenatal treatments for only certain fetuses with LUTO.

What happens after fetal treatment for LUTO?

A baby who has received fetal treatment for LUTO will need to be delivered in a hospital with a neonatal intensive care unit (NICU). After delivery, the NICU can do more testing to figure out the cause of the LUTO.

Depending on the exact diagnosis, surgery may be needed to create a permanent way for urine to leave the baby’s body. Therapies dialysis and kidney transplant may also be needed.

How sick a baby will be after birth depends on how severe the lung and kidney damage are and the cause of the LUTO.

Source: https://www.hopkinsmedicine.org/health/conditions-and-diseases/lower-urinary-tract-obstruction

Johns Hopkins Gazette | February 12, 2007

Lower Urinary Tract Obstruction | Johns Hopkins Medicine
Millions of middle-aged and older men experience the symptoms of an enlarged prostate multiple times during the day and night.

What they may not know is that the disease known as BPH (for benign prostatic hyperplasia), marked by urgency and frequent urination, is not one but at least a pair of disorders, and that one of the pair — tied to a newly identified gene — has far more serious implications.

In a study published in the February issue of The Journal of Urology, researchers at Johns Hopkins reported finding substantially higher levels of a protein made by a gene known as JM-27 in men whose BPH is more severe and more ly to lead to bladder-related complications if left untreated.

Although BPH affects the prostate, the resulting symptoms are often called “lower urinary tract symptoms.” These symptoms reflect not only the direct effects of the prostate on urinary flow and urgency but functional changes in the bladder that result from the increased pressure.

The Johns Hopkins team, led by Robert Getzenberg, also developed a blood test that detects the JM-27 protein in men with severe symptoms. The JM-27 diagnostic test, if eventually approved by the FDA, could be used to identify men with this highly symptomatic form of the disease early, before there is any damage to the bladder or urinary tract.

“Our experiments show that the expression of this marker is related to the presence of the severe form of BPH and not to the size of the prostate or to the presence or risk of prostate cancer,” Getzenberg said.

“What we're looking at is two diseases: BPH that produces more mild symptoms and is less ly to lead to bladder and other urinary tract damage, and BPH that is highly symptomatic with increased potential to do damage to the bladder.”

In their latest study, Getzenberg and his team tested blood samples taken from 85 men; 29 had either no detectable BPH symptoms or mild ones, 39 experienced more marked symptoms of the disease, and 17 had confirmed prostate cancer.

The blood of all patients was not only screened for the presence of the JM-27 protein but also analyzed to determine exactly how much JM-27 was in the bloodstream of each man. Researchers found a “statistically significant” difference in the levels of JM-27 in the men who were either completely asymptomatic or had mild symptoms of BPH.

Men with higher levels of JM-27 had the less severe form of BPH, whereas men with low levels of JM-27 had the worse form of the disease their symptoms.

And the presence of prostate cancer did not throw these results off; in other words, even in these men, it could be determined, their levels of JM-27, whether they suffered from the mild or severe form of BPH.

Getzenberg says the new biomarker test detects approximately 90 percent of the men with the severe form of BPH and incorrectly classifies men as having this form of the disease in only 23 percent of the cases.

Current medical therapy for men who suffer from BPH is with two classes of drugs: alpha blockers, which relax the prostate, and 5-alpha reductase inhibitors, which help to shrink it. Forms of BPH that do not respond to medical therapies frequently require surgical intervention.

“The next step is to figure out which drugs work best on which form of the disease as differentiated by JM-27,” Getzenberg said.

The incidence of BPH is estimated to equal the age of the men. Therefore, 50 percent of men in their 50s have the disease, and the incidence increases to 80 percent for those in their 80s.

Source: https://pages.jh.edu/~gazette/2007/12feb07/12prost.html

Urinary Tract Infection, Complicated (UTI)

Lower Urinary Tract Obstruction | Johns Hopkins Medicine

— The first section of this topic is shown below —

  • Among the most common, resistant strains frequently encountered:
    • Enterobacteriaceae
    • Pseudomonas aeruginosa 
    • Acinetobacterspp.
  • Less common:
    • MSSA or MRSA
      • Most due to invasion of urinary tract (secondary to catheters, stents)
      • Consider presentations of staphylococcal bacteremia with findings of S. aureus in urine.
    • Enterococcus spp. (including VRE)
    • Candida spp.
    • Fastidious organisms possible.
  • Infections may be polymicrobial, especially if chronic urinary catheter or stents are present.

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  • Among the most common, resistant strains frequently encountered:
    • Enterobacteriaceae
    • Pseudomonas aeruginosa 
    • Acinetobacterspp.
  • Less common:
    • MSSA or MRSA
      • Most due to invasion of urinary tract (secondary to catheters, stents)
      • Consider presentations of staphylococcal bacteremia with findings of S. aureus in urine.
    • Enterococcus spp. (including VRE)
    • Candida spp.
    • Fastidious organisms possible.
  • Infections may be polymicrobial, especially if chronic urinary catheter or stents are present.

There's more to see — the rest of this entry is available only to subscribers.

Melia, Michael, and James DeMaio. “Urinary Tract Infection, Complicated (UTI).” Johns Hopkins ABX Guide, The Johns Hopkins University, 2017. Johns Hopkins Guide, www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540573/all/Urinary_Tract_Infection__Complicated__UTI_. Melia M, DeMaio J. Urinary Tract Infection, Complicated (UTI). Johns Hopkins ABX Guide. The Johns Hopkins University; 2017. https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540573/all/Urinary_Tract_Infection__Complicated__UTI_. Accessed May 18, 2020.Melia, M., & DeMaio, J. (2017). Urinary Tract Infection, Complicated (UTI). In Johns Hopkins ABX Guide. The Johns Hopkins University. Retrieved May 18, 2020, from https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540573/all/Urinary_Tract_Infection__Complicated__UTI_Melia M, DeMaio J. Urinary Tract Infection, Complicated (UTI) [Internet]. In: Johns Hopkins ABX Guide. The Johns Hopkins University; 2017. [cited 2020 May 18]. Available from: https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540573/all/Urinary_Tract_Infection__Complicated__UTI_.* Article titles in AMA citation format should be in sentence-caseMLAAMAAPAVANCOUVERTY – ELECT1 – Urinary Tract Infection, Complicated (UTI)ID – 540573A1 – Melia,Michael,M.D.AU – DeMaio,James,M.D.Y1 – 2017/05/16/BT – Johns Hopkins ABX GuideUR – https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540573/all/Urinary_Tract_Infection__Complicated__UTI_PB – The Johns Hopkins UniversityDB – Johns Hopkins GuideDP – Unbound MedicineER –

Source: https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540573/all/Urinary_Tract_Infection__Complicated__UTI_

Frequency

Significant lower urinary tract obstruction can be found in 1 in 5000 pregnancies.

Diagnosis and Prognostic Criteria

The diagnosis of LUTO is made by prenatal targeted ultrasound. Typically, the baby’s bladder is very distended (swollen). The presence of a “key-hole” sign is suggestive of posterior urethral valves, particularly in a male fetus.

There may be variable degrees of dilation of the upper urinary collection system. The ultrasound findings of the baby’s kidneys should be carefully assessed for evidence of damage. Assessment of amniotic fluid volume as well as the presence of other potential structural abnormalities is sought.

Once the diagnosis of LUTO is established, the prognosis for survival is then assessed. The baby’s outcomes have been correlated to the kidney function as assessed prior to treatment. There are two methods to determine the prognosis before surgery.

These methods are called fetal vesicocentesis, which samples the baby’s urine, and cordocentesis, which samples the baby’s blood. Genetic studies are also performed.

  1. Fetal Vesicocentesis: Fetal kidney function may be obtained by performing sampling of the baby’s urine by placing a thin needle into the baby’s bladder and draining the urine. If the results of the first drainage are below the threshold values then fetal therapy may be offered. If the first vesicocentesis shows values above the threshold, a repeat vesicocentesis will be performed in 48 hours.
  2. Cordocentesis: An alternative to vesicocentesis is to perform a cordocentesis. Under ultrasound guidance, a needle is placed in the umbilical cord. Fetal blood is drawn and sent for a serum Beta-2-microglobulin level. If the serum Beta-2-microglobulin level is less than 5.6 then fetal therapy may be offered.

Management Options and Outcomes

The ability to evaluate kidney function is somewhat imprecise. This probably reflects the different diagnoses responsible for the sonographic findings, which do not have a similar prognosis despite comparable fetal urinary findings or vice versa. Despite this limitation, the follow treatment options are available:

  1. Expectant Management: This approach entails frequent ultrasound assessment to assess progression during the pregnancy. After delivery, pediatric specialists will evaluate the baby and subsequently offer treatments at that time. The risk of this approach is that further kidney and lung damage may occur during the pregnancy. In the setting of oligohydramnios (low amniotic fluid volume), the expected perinatal mortality rate is 77%. Pregnancies where the obstruction only affects one kidney have a very good prognosis. These pregnancies can be monitored regularly by ultrasound and will ly deliver at full term.
  2. Vesicoamniotic Shunt: Fetal urinary diversion procedures have been performed since the 1980’s. Essentially, a shunt is placed between the baby’s bladder and the amniotic fluid, thus relieving the blockage. This approach is meant to prevent further kidney and lung damage. The final treatment of the obstruction is performed after the birth of the child. In cases that have been determined to be in the favorable prognostic category (see above), the approximate perinatal survival using this treatment approach is 66%, of which half will have significant kidney damage and may need dialysis or kidney transplant. Risks of shunt placement include dislodgement/blockage/malfunction (25%) thus requiring multiple shunt placements during the pregnancy, urinary ascites (leakage of urine from the bladder into the baby’s abdomen), and fetal death (4%).
  3. Fetal Cystoscopy and Treatment of LUTO: This approach allows for direct visualization of the baby’s bladder, proximal urethra, and ureteral orifices. This approach, which was developed by Dr. Ruben Quintero, has the theoretic advantage of providing a more precise diagnosis. The ability to establish the correct diagnosis prenatally may improve the counseling capacity. In addition, ablation of posterior urethral valves or other in utero endoscopic treatments of fetal lower urinary tract obstruction may be performed. Whether these theoretical advantages translates into improved perinatal outcomes remains to be proven, which is why this and other centers are conducting studies in this regard. Risks from placing a needle or trocar into the fetal bladder include: infection, bleeding, trauma to the baby such as iatrogenic gastroschisis (hole in the abdominal wall lack the protrusion of the abdominal contents into the amniotic cavity), thermal damage to surrounding structures, or fetal death (4%). The details of the possible diagnostic and treatment approaches are detailed below..

Candidacy for Fetal Treatment

The following criteria generally must be met to offer fetal therapy for LUTO:

  1. Gestational age: 16 weeks 0 days to 30 weeks 0 days.
  2. Sonographic evidence of LUTO.
  3. Fetal renal values below threshold shown in items 5 and 6 listed below.
  4. Twin gestation may be included.

Details of Procedures

The procedure(s) will be performed under local anesthesia. Fetal anesthesia will be delivered to the fetus with a fine needle under ultrasound guidance prior to entering the fetal bladder. Techniques

  1. Vesicoamniotic catheter placement: A vesicoamniotic shunt will be placed in all cases over a wire guide. This can be done under ultrasound guidance. Endoscopic documentation of adequate shunt placement may be performed as well. Vesicoamniotic shunting may be necessary several times during the pregnancy due to dislodgement of the shunt or continued urinary outlet obstruction.
  2. Diagnostic Fetal Cystoscopy: After a 2-3 millimeter skin incision is made, and under ultrasound guidance, an operative fetoscope will be inserted through the mother’s abdomen and uterus into the fetal bladder. The bladder wall, mucosa, trigone, and urethra will be the targets of the endoscopic assessment.
  3. Operative Cystoscopy: If posterior urethral valves are identified, the valves will be ablated using laser energy through a contact YAG laser fiber. Similarly, an obstructive ureterocele may be incised within the fetal bladder with a contact laser fiber. There may be rare circumstances that fetal urethral patency (unblocked condition) may be assessed with a soft wire guide. If patency is documented, a thin transurethral catheter may be placed over a wire guide. Finally, spontaneous or iatrogenic urinary ascites (diversion of urine from the bladder into the baby’s abdomen) may occur. In these cases, access to the fetal bladder may best be achieved by fetal hydrolaparoscopy. An incision is made over the bladder dome with YAG laser energy, until the inside of the bladder can be seen. If the urethra can be accessed and the posterior urethral valves can be ablated, this is done at this point. Otherwise, surgery is completed by placing a peritoneoamniotic shunt.

Postoperative Care

Before birth, it is recommended that ultrasound assessment occur every week for the first four weeks, then every three to four weeks thereafter.

Ultrasound parameters of particular importance include the amount of amniotic fluid volume, measurement of the fetal bladder, assessment of the fetal kidneys and urinary collection system, presence of urinary ascites, and location of the vesicoamniotic shunt.

After birth, the child will be evaluated by pediatric specialist and may require further tests and treatments.

Additional Resources

Source: https://www.fetalhealthfoundation.org/fetal-syndromes/lower-urinary-tract-obstruction/