To review the data in Ethnic Emirati population 
to see if reflex Anuria is a Gender specific and 
ethnically neutral phenomenon.
Acute renal failure (ARF) can manifest 
secondary to urinary tract obstruction. The 
outflow tracts of both kidneys must be 
obstructed to cause ARF, unless preexisting 
renal dysfunction is present in which case the 
obstruction may involve only a single kidney.
In a small number of patients ARF can occur 
with unilateral ureteric obstruction in the 
presence of normal contralateral kidney 
function. This phenomenon is known as reflex 
anuria.
Varying mechanisms have been proposed to 
explain reflex anuria. The first is that it results 
from a neurovascular reflex causing profound 
arteriolar vasoconstriction and bilateral ureteric 
spasm secondary to unilateral ureteric or renal 
parenchymal damage. The uretero-renal or 
reno-renal reflexes are examples of the 
neurovascular mechanism.
Previous publication of case series in Caucasian 
population by the author (1) showed all patients 
were male with a normal contralateral kidney 
on CT scan. No female patients developed reflex 
anuria during the reviewed case series.

We reviewed the incidence of Reflex Anuria 
in Acute Unilateral Ureteric obstruction 
secondary to urolithiasis in Emirati males 
and females during a period of 12 months
The data were verified, coded, and analyzed 
using IBM-SPSS 21.0 (IBMSPSS Inc., Chicago, 
IL, USA). Descriptive statistics including 
means, standard deviations, medians, 
ranges, and percentages were calculated. 
The chi-square test was employed to 
compare frequency distribution differences 
among various groups. For continuous 
variables, independent t-tests were used to 
bifurcate the creatinine levels with respect 
to sex. A significance level of p ≤ 0.05 was 
considered statistically significant.

97 patients were included in the retrospective 
study. The mean age of the participants was 
37.8 years with a standard deviation (SD) of 
13.6, while the median age was 36 years, 
ranging from 16 to 82 years. Among the 
participants, 44 (45.4%) were male and 53 
(54.6%) were female.
The mean creatinine level was 77.5 μmol/L with 
a SD of 25.4, and the median creatinine level 
was 73.0 μmol/L, ranging from 27 to 204 
μmol/L. Among the creatinine categories, 12 
(12.4%) 
patients had abnormal levels, while 36 (37.1%) 
males and 49 (50.5%) females had normal 
levels according to gender-specific ranges.
Significant differences were observed in 
creatinine levels (p = 0.001) and creatinine 
categories (p = 0.001) with males having higher 
creatinine level when compared to females.
These findings suggest a significant association 
between sex and creatinine levels, highlighting 
potential sex-based differences in renal 
function among patients with reflex anuria in 
acute obstructing urolithiasis

One possible explanation for reflex anuria, 
secondary to obstructing urolithiasis, not 
occurring in women is possibly due to the 
vasodilatory effect of progesterone which may 
contribute to ureteric dilatation facilitating 
stone passage. As demonstrated in this study 
this phenomenon is gender specific and 
ethnically neutral

It is important we appreciate the concept of 
reflex anuria as some patients with smaller 
stones can be managed conservatively with 
medical expulsive treatment as the renal failure 
is reversible and the patient would be spared 
the risks of a general anaesthetic and a surgical 
procedure

1)Khan MH, Hari Krishnan JA, Jones GE, Mir K (2013)  Reflex Anuria Secondary to Unilateral Ureteric Obstruction  by Urolithiasis: is it a Gender Specific Phenomenon? Med  Surg Urol 2: 113. doi:10.4172/2168-9857.1000113