Small Kidney? Big Problem

By: Deavyn Edwards

Nothing is more terrifying to a new parent than the prospect of their newborn child having a serious, chronic health problem. Kidney disease is among the myriad of health issues that can follow infants throughout childhood and even into adulthood. I was born with a small kidney, 15% the size of a normal kidney, and my health problems continued until age 10 when I was given surgery to correct the biggest symptom of having small kidneys: ureteral reflux.

Children who are born with a small kidney, especially boys, often grow up having to deal with issues like chronic ureteral reflux, a problem where urine flows backwards from bladder to kidney instead of regularly, from kidney to bladder. Ureteral reflux can lead to repeated urinary tract infections and further kidney damage if it is left untreated. The causes, detection, and implications of being born with a small kidney were examined in an article by Japanese scientists in Kidney International (see Figure One).

My condition was not detected as quickly as the babies studied in Kidney International. These authors formed a population sample of 4,000 apparently healthy babies, of which 2,129 were male and 1,871 were female, with a median age of 3 days (811). In my case, the small kidney went undetected until I was three and a half years old. The symptoms of ureteral reflux – uncontrollable and painful urination – were continually misdiagnosed as conditions such as strep throat. However, the eventual correct diagnosis of my small kidney did happen similarly to the diagnoses of the studied babies. The infants were given ultrasound scans and their kidney sizes checked. If one kidney appeared to be small – defined as “2.0 cm less than the contralateral kidney” (811) – or if both seemed to be on the low end of normal (see Figure Two), then the child’s parents were encouraged to bring their infants back for continued testing and measurement (812). The diagnosis of my small kidney came from its relative size to the other kidney, not a simple measurement.

The authors expected that these sorts of urinary infections would be much more prevalent in infants with abnormal kidney sizes, hypothesizing that increased rates of ureteral reflux would predict increased rates of urinary infection (813). Despite the absence of any family history of urinary infections, ureteral reflux was found in eight small kidneys belonging to seven patients (813). One method of determining infection was the rate of DMSA uptake (813). Still, the authors found that within the median 1.8 year follow up period, none of the patients developed a urinary infection (813). The authors also kept tabs on the kidneys’ growth rates. Although both kidneys grew, with the larger kidney sometimes growing faster than normal, the smaller kidney tended to grow less than a normal (814). Ureteral reflux was the main symptom of my small kidney, and I lived with it until I was ten years old. Just like in the article, it turned out that for me, ureteral reflux did not really cause continual urinary tract infections. Still, the condition was painful.

The data from this study indicates that most people with small kidneys have had them since birth (814). This suggests that “congenital maldevelopment” is the major cause of small kidneys (815). The authors also found that, in conjunction with known incidence rates, seven of their eight patients were male, despite the fact that most adults found to have small kidneys are females (815). This could be explained by the fact that in the absence of scanning like the study subjects received, adult females learn they have small kidneys after being treated for repeated urinary infections, which are much more common in women than men (815). Because women notice these urinary tract infections more often than men, they in turn are found to have small kidneys more often. Still, this study indicated high incidence rates in males; considering the potential for severe, long-term renal damage, the authors conclude their study by saying infant boys should be scanned and examined to check for kidney abnormalities.

Being given an ultrasound at birth and at certain checkpoints to keep an eye on my kidney’s growth may have prevented a decade of living under the painful symptoms of ureteral reflux and the continual misdiagnosis of the root cause. Because no one thought my issues stemmed from an abnormal kidney, it took years for that issue to be considered. Fortunately, I was able to have surgery that eliminated the biggest complication of my small kidney. Still, spending a large portion of my early childhood in and out of the hospital to be examined, operated on, and tested was difficult to grow up with. Earlier detection would have been a much better situation for my doctors and myself.

Figure One

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Figure Two

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Works Cited

Hiraoka, Masahiro, Chikahide Hori, Hirokazu Tsukahara, Kenkou Kasuga, Yoshinori Ishihara, and Masakatsu Sudo. “Congenitally Small Kidneys with Reflux as a Common Cause of Nephropathy in Boys.” Kidney International 52 (1997): 811-16. Print.
doi:10.1038

 

writing in the natural sciences