UNDERSTANDING CAKUT: SYMPTOMS, DIAGNOSIS, AND MANAGEMENT
Medically Reviewed by Dr. Sony Sherpa (MBBS)
Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are a group of congenital deformities that affect the development of the kidneys and urinary tract. These anomalies can manifest as mild or severe and significantly impact a person's health and quality of life.
CAKUT occurs in nearly 1 out of every 500 live births, comprising 40-50% of end-stage renal disease cases in children.[1]
This blog surveys what is known about the different types of CAKUT, their causes and symptoms, risks and complications, diagnosis and early detection, living with CAKUT, treatment options, and the latest advancements and innovations in managing this condition.
Types of CAKUT
There are several types of CAKUT[2], each affecting different parts of the kidney and urinary tract. Some of the most common types include:
Kidney Malformations
The structure and function of the kidneys and collecting ducts, including the ureters that connect the kidneys to the bladder, are affected by renal abnormalities.
Congenital kidney and ureter malformations include:
- Single-Arched or Horseshoe Kidney: In this condition, the two kidneys fuse at the lower part, forming a horseshoe-shaped kidney. This anomaly can sometimes cause no issues but can be associated with other kidney problems.
- Kidney Agenesis: Kidney agenesis is when one or both kidneys fail to develop correctly. This can lead to an array of challenging complications and kidney failure. ANOS1, EYA1, and RET mutations may cause this CAKUT.
- Polycystic Kidney Disease: Kidney cysts are a characteristic of polycystic kidney disease, a hereditary condition. These cysts can lead to kidney damage and other complications. Gene mutations in PKD1 contribute to causing up to 85% of cases.
- Multicystic Dysplastic Kidneys (MCDK): MCDK is a condition where one or both kidneys have multiple cysts and do not function properly. This can induce eventual kidney failure and other complications. Mutations in Gdnf-RET associated with MCDK onset.
- Renal Hypoplasia: Renal hypoplasia is a condition where one or both kidneys are underdeveloped. This can affect kidney function and lead to health complications.
- Duplex Kidneys: Duplex kidneys, also known as a duplicated collecting system, refers to a condition where a person has two ureters from one kidney instead of the usual single ureter. This anomaly can increase the risk of infections and other kidney issues.
- Megaureter: This is a condition where the ureters are more comprehensive than usual.
Urinary Tract Anomalies
The urethra is the tube that diverts urine from the bladder out of the body. Collectively, the bladder and urethra are known as the urinary tract.
Obstruction or urinary reflux can occur at different points in the urinary tract. Obstruction can lead to complications such as hydronephrosis. The swelling of the kidneys characterizes hydronephrosis due to the buildup of urine. Common causes include obstruction, reflux, or other urinary tract abnormalities.
Some of the specific anomalies of the urethra include:
- Ureteropelvic Junction Obstruction (UPJO): UPJO is a blockage at the meeting place between the ureter and the kidney. This blockage can cause urine to return to the kidney, leading to swelling and potential damage.
- Posterior Urethral Valves (PUV): PUV is a condition where extra flaps of tissue form in the urethra. These flaps can obstruct urine flow, leading to bladder and kidney damage.
- Ureterovesical Junction Obstruction or Ureterocele: This condition involves an obstruction at the connecting point between the ureter and the bladder, leading to urine backup and potential kidney damage.
- Vesicoureteral Reflux (VUR): Reflux, specifically vesicoureteral reflux (VUR), occurs when urine from the bladder flows backward into the ureters and kidneys. This can increase the risk of infections and kidney damage.
- Hypospadias: Hypospadias is a condition where the urethra’s opening is misaligned, found on the underside of the penis instead of the tip. This anomaly can affect urinary function and may require surgical correction.[3]
- Bladder Exstrophy: Bladder exstrophy is a rare condition where the bladder develops outside of the abdominal wall.[4] This condition can affect the structure and function of the urethra, leading to urinary challenges.
- Prune Belly Syndrome (Eagle-Barrett Syndrome): Prune belly syndrome is a congenital disorder represented by the lack or severe weakness of abdominal muscles, undescended testicles, and urinary tract anomalies, including abnormalities in the urethra.[5]
These anomalies of the urethra can vary in severity and may require medical intervention, such as surgical correction, to improve urinary function and prevent complications. It is essential to consult with a healthcare practitioner for an optimal diagnosis and effective management of these conditions.
CAKUT Causes
The exact cause of CAKUT is not fully understood. It is likely to be a combination of genetic and environmental factors. Some of the known risk factors for CAKUT include:
- Autosomal Dominant or Autosomal Recessive inheritance patterns
- Genetic mutations in renal developmental genes, such as mutations in Pax2 and BMP4 (alongside mutations specific to the CAKUT itself)
- Exposure to certain medications, like ACE inhibitors, or toxins during pregnancy
- Diabetes or high blood pressure during pregnancy
Other causes of CAKUT include conditions that influence multiple body systems[6], such as:
- Renal coloboma syndrome
- 17q12 deletion syndrome
- RCAD syndrome
- Fraser syndrome
- Townes-Brocks syndrome
- Branchio-oto-renal syndrome
Symptoms and Complications
The symptoms of CAKUT can vary depending on the type and severity of the condition. Some common symptoms include[7]:
- Abnormal urine output (too much or too little)
- Urinary tract infections (UTI)
- High blood pressure
- Swelling in the hands, feet, or face
- Abdominal pain
- Difficulty urinating
- Blood in the urine
- Frequent urination
- Poor growth or weight gain in infants and children
If left untreated, CAKUT can lead to a range of complications. Between 40 and 50% of children with end-stage chronic kidney disease and kidney failure have a CAKUT[8].
UTIs and high blood pressure can also present as complications due to CAKUT.[9] [10] Other possible complications include:
- Growth and developmental delays in children
- Increased risk of kidney stones
- Increased risk of bladder and kidney cancer
Can CAKUT be Prevented?
As the exact causes of CAKUT are not fully understood, there are no guaranteed prevention methods. Here are some suggestions for lowering the risk of CAKUT occurrence during pregnancy:
- Avoid exposure to harmful substances during pregnancy
- Manage chronic health ailments, especially diabetes and high blood pressure, before and during pregnancy
- Genetic counseling for families with a history of CAKUT or other kidney and urinary tract disorders
Diagnosis and Early Detection
CAKUT is often detected during routine prenatal ultrasounds. Further testing, such as a fetal MRI or amniocentesis, may be necessary if a potential anomaly is detected.
After birth, if a child shows symptoms of CAKUT, a pediatrician may order tests, such as ultrasound or CT scan, to assess the structure of the renal system and urinary tract. Blood and urine tests may assist in checking for abnormalities[11].
A standard urodynamic test is a voiding cystourethrogram (VCUG) that helps reveal urinary obstructions or reflux. It is a type of renal scan that involves catheterization of the urethra, along with either fluoroscopy or a radionuclide injection, to follow the urine flow on an imaging device.
Early detection is crucial in managing CAKUT and preventing potential complications. Therefore, attending all recommended prenatal and follow-up appointments for infants and children is essential.
CAKUT Treatment Options
The treatment for CAKUT will depend on the type and severity. In some cases, no treatment may be necessary, and the condition resolves independently. In other cases, treatment can correct problems with urine flow and prevent or manage complications.
Some standard treatment options for CAKUT include:
- Using antibiotics to treat or prevent infections of the urinary tract
- Surgery to correct structural abnormalities or blockages
- Medications for the treatment of high blood pressure or other symptoms[12]
- Dialysis or kidney transplant in cases of kidney failure
There are several commonly deployed surgical techniques used to treat various CAKUT with varying degrees of success.[13] Examples include:
- Laparoscopic Pyeloplasty: This is a minimally invasive surgical procedure used to treat ureteropelvic junction obstruction. It involves making small surgical cuts with a laparoscope to reconstruct and widen the narrow portion of the ureter where it meets the kidney, allowing for improved urine flow.[14]
- Ureteral Reimplantation: Ureteral reimplantation is a surgical procedure to correct vesicoureteral reflux (VUR).[15] It involves repositioning the affected ureter to create a new tunnel in the bladder wall, helping to control the flow of urine and prevent reflux, lowering the risk of infections and kidney damage.
- Endoscopic Correction: Also known as endoscopic valve ablation[16], this is a minimally invasive procedure involving an endoscope, which is a thin, flexible tube with a camera attached. The procedure can treat various CAKUT conditions, such as ureteral strictures or ureteral stones, by accessing the urinary tract through the urethra or a small incision and using specialized tools to correct the issue.
- Stenting: Stenting is a procedure that involves the placement of a small tube (stent) in the urinary tract to improve the flow of urine.[17] Stenting can treat various CAKUT conditions, such as ureteral strictures or obstructions, to keep the affected area open and allow urine to pass through freely.
It is essential to discuss the risks of surgery with a doctor carefully before making a decision.
Managing CAKUT requires a multidisciplinary approach involving a team of specialists, including pediatric nephrologists, pediatric urologists, and genetic counselors. The treatment plan relies on the individual's requirements and includes a combination of medication, surgery, and lifestyle changes.
Regular check-ups and screenings are crucial in managing CAKUT and preventing potential complications. Following the recommended treatment plan and attending all follow-up consultations is essential for the best possible outcome.
Prognosis and Living with CAKUT
The prognosis for individuals with CAKUT can vary based on the type and severity of the condition. In some cases, the condition may resolve independently, while in others, it may require ongoing management and treatment. With early detection and proper management, many individuals with CAKUT can lead healthy, fulfilling lives.
Living with CAKUT can be challenging, both physically and emotionally. It is essential to have a robust support system and access to resources and information to manage the condition effectively.
Some tips for living with CAKUT include:
- Educate yourself and your family about the condition and its management
- Follow a healthy diet and exercise regularly to maintain overall health
- Stay hydrated and monitor urine output
- Take medications as prescribed by a doctor
- Attend regular check-ups and screenings
- Seek support from a therapist or support group if needed
Latest Advancements and Innovations
Significant strides have been made in diagnosing and treating CAKUT due to advancements in technology and medical research.
Some of the latest advancements and innovations in managing this condition include:
- Genetic testing to identify specific mutations in renal developmental genes[18]
- Minimally invasive surgical techniques for correcting structural abnormalities
- Robotic surgeries for enhanced accuracy[19]
- Improved medications for managing symptoms and preventing complications
- Stem cell therapy for repairing damaged kidney tissue[20]
Conclusion
An individual's health and quality of life may be greatly impacted by Congenital Anomalies of the Kidney and Urinary Tract (CAKUT), a group of congenital disabilities. Detecting and managing the issue early on is crucial in preventing potential complications and improving outcomes. With the latest advances in medical research, there is hope for individuals living with CAKUT to lead healthy, fulfilling lives. If you or a loved one has been diagnosed with CAKUT, it is essential to work closely with an expert team to devise a personalized plan and ensure the best possible outcome.
To search for the best Urology healthcare providers in Croatia, Germany, Hungary, India, Malaysia, Poland, Singapore, Slovakia, Spain, Thailand, Turkey, UAE, UK and the USA, please use the Mya Care search engine.
To search for the best healthcare providers worldwide, please use the Mya Care search engine.
Sources:
