Case Report - (2021) Volume 7, Issue 11
Bilateral Renal Agenesis is not compatible in extrauterine life. Pulmonary hypoplasia develops in the absence of amniotic fluid, causing severe respiratory insufficiency at birth. Renal agenesis can result from the complete regression of a dysplastic kidney. It might be a unilateral or bilateral problem. A preexisting diabetic condition is linked to bilateral renal agenesis. The majority of instances of bilateral agenesis are sporadic. However, genetic variables have a role in pathogenesis, and multifactorial inheritance is a plausible explanation, exact manner of genetic inheritance is unclear. There have also been reports of X-linked, autosomal recessive, and autosomal dominant inheritance. Bilateral/unilateral renal agenesis, renal hypodysplasia (a reduction in the number of nephrons resulting to a small overall kidney size and frequent dysplasia with or without cysts), and multicystic dysplastic kidneys are all examples of developmental renal abnormalities (MCDK).A kidney can be missing because it never developed (agenesis [possibly rare]) or because a dysplastic kidney has completely regressed (aplasia/MCDK). The term "renal agenesis" will be used in the following topic review to refer to missing kidneys caused by either of these etiologies. The youngster who lived the longest lived for 39 days among various cases. However, in bilateral renal dysplasia treated with continuous intrauterine amnioinfusion, a 9-month survival rate was seen in generally. Diagnosis of this condition is made by various investigations like NT scan with double markers, Ultrasonography, per abdominal examination. Awareness about the patient’s condition and counselling of relatives was done. Termination of pregnancy was done in this case.
Renal Agenesis; Pulmonary hypoplasia; Dysplastic kidney; Ultrasonography
Bilateral/Unilateral renal agenesis is a rare condition which is seen during gestational period. This condition is results from regression of a dysplastic kidney. In these cases various renal abnormalities are seen. Abnormalities like bilateral senile kidney, bilateral multiple renal cyst dysplasia, bilateral polycystic kidney, unilateral absent kidney with unilateral polycystic dysplastic kidney. Diagnosis of such condition is made by various scans like NT scan, ultrasound examination, and various markers during gestational period which confirms the findings. Some cases presented with various other conditions like low volume of amniotic fluid. It may lower accuracy of diagnosis using ultrasound to examine the presence and structure of the fetal kidneys. These conditions are resolved by termination of pregnancy by counselling parents and relatives.
Patient information & Clinical findings
A 27-year-old female G2P1L1 at 13 week of gestation came for standard antenatal treatment. Patient’s medical & obstetric history was unremarkable. Previous female child was a full term normal vaginal delivery. She is being screened for any renal abnormalities and found out to be normal.
Diagnostic assessment
She was subjected for NT scan and double markers both were normal. Ultrasound examination was done suggestive of single live intrauterine fetus with gestational age 12 week, changing presentation, liquor adequate. On follow-up visit after 1 month per abdomen examination lag of 2 week felt and liquor seemed to be negligible so repeat ultrasound was done. Suggestive of single live intrauterine fetus 17.6 week with breech presentation, liquor zero. On examination, both the fetal kidneys could not be visualized in renal fossa or at ectopic site. During the whole trial period, the foetal urine bladder could not be distinguished.
Therapeutic intervention & Outcomes
Patient and relatives were informed and counselled about the same. The risks associated with the condition and probable cause to be sporadic was explained.
Pregnancy was terminated and a stillborn male baby was delivered. Physical examination of stillborn baby revealed a low set ears, a flat nose, dehydrated skin, wide set eyes, receding chin. Postmortem ultrasound of stillborn baby revealed absence of both the kidneys in renal fossa as well as pelvic cavity.
Bilateral Renal Agenesis is a rare condition with incidence being 01 in 3000 live birth [1]. Males are 2.5 times more prone than females for this condition [2]. It’s a lethal anomaly incompatible for extrauterine life. Male gender affected more than females with high rate of left sided agenesis [3].
There are three stages of development of the renal structure:
Metanephric blastema known as invasions by ureteric bud to a cord of mesenchymal cells at 5 weeks of gestation.
The pronephros which is non-functioning structure develops from the intermediate mesoderm in the cervical region and then regresses at approximately four weeks embryonic age. The mesonephros, which develops from the paravertebral mesoderm of the upper thoracic to lumbar area, takes its place at around five weeks.
The mesonephros disappears at conclusion of second month of pregnancy. In males, certain caudal tubules around the testis and ovaries grow into the vas deferens, and in females, residual tissue. The growth of the dorsomedial wall of the mesonephric duct is called the ureteric bud.
Metanephric blastema are the invasions by ureteric bud to a cord of mesenchymal cells at 5 weeks of gestation which leads to the formation of the definitive kidney. Nephrons and collecting system defines the beginning of functioning renal unit. Metanephros which is a tissue forms the permanent kidney.
Glomeruli and tubules begin to function at 6 to 10 weeks of gestation and starts to produce urine at approximately 11 weeks. Then migration of definitive kidney from caudal position to lumbar region takes place. Rate of detection of bilateral renal agenesis by ultrasound was reported 84% & 91% and detection rate for unilateral renal agenesis was 59% &80% [4, 5].
On ultrasound in first trimester, fetal kidneys are relatively hyperechoic and they can be visualised at both sides of the lumbar spine starting at 10 to 12 weeks [6,7].
According to a study, the bladder visualized when the crown rump length (CRL) more than 67 mm, and 91 percent of cases when the crown rump length was 38 to 67 mm [8]. Therefore, the bladder should be observed for accumulation of urine for 1 hour before reaching on conclusion that urine is not being produced [9].
Severely reduced or absent amniotic fluid is major nonspecific marker of renal bilateral agenesis. The primary source of amniotic fluid in early pregnancy is assumed to be fluid flow across the amnion, foetal membranes, and chorionic plate. Urine of foetus becomes the main source after approximately 16 weeks of pregnancy. So, volume of amniotic fluid in pregnancies which are complicated by agenesis of kidney appears to be normal in early phase of gestation, sharply reduced or absent amniotic fluid volume is the most prominent ultrasonic feature of this disorder in midtrimester [10].
Color (Doppler)
When the kidneys aren't visible, Doppler imaging of the renal arteries should be done. Color flow imaging of renal vessels is not possible. Doppler imaging with proper low gain settings is suggestive, but not conclusive, of renal agenesis. Color flow, on the other hand, the presence of renal tissue is established by Doppler demonstration of renal vessels, which is validated by waveform analysis. On postmortem examination of seven of eight fetuses with bilateral renal agenesis and one of eight fetuses with unilateral agenesis with contralateral atrophic multicystic kidney in a study that correlated prenatal colour imaging with postnatal evaluation, absent renal blood flow was noted in seven of eight fetuses with bilateral renal agenesis and one of eight fetuses with unilateral agenesis with atrophic multicystic kidney. On postnatal evaluation, three fetuses had just one renal artery visualized; two of these had unilateral agenesis and one had a multicystic dysplastic kidney. In all fetuses with both renal arteries discovered prenatally, the presence of both kidneys was verified postnatally.
Adrenal gland outcomes
The adrenal gland or intestine can fill an empty kidney pit and mimic kidney tissue if proper care is not given for an elderly kidney or renal ectoderm. The adrenal gland appears flattened on parasitic imaging and migrates laterally and lower with a central hypoechoic layer sandwiched between two hypoechoic areas
Bladder findings
Fetal bladder filling and emptying is the best indicator of fetal urine production. Failure to visualize the fetal bladder associated with oligohydramnios suggests severe disease. In a series of pregnancies with unresected fetal bladder at 16 to 24 weeks gestation, the following serious anatomical malformations were present: bilateral senile kidney, bilateral multiple renal cyst dysplasia, bilateral polycystic kidney, unilateral absent kidney with unilateral polycystic dysplastic kidney and normal kidney, but ectopic ureter and conical bladder. Although infants had anatomically normal urinary tracts at autopsy, had Turner syndrome with cystic fibrosis and severe intrauterine growth retardation, possibly related to dysfunction of the urinary system.
The role of diagnostic amniotic fluid infusion - the absence of amniotic fluid significantly reduces the ability of ultrasound to examine the presence and structure of the fetal kidneys. Impairment of visualization is exacerbated by congestion of the limbs of the fetus adjacent to the trunk. Insufficient visualization of the anatomy of the fetus due to lack of amniotic fluid is a major obstacle to the accurate diagnosis of bilateral renal aplasia.
Role of magnetic resonance imaging
T2-weighted magnetic resonance imaging (MRI) is characterized by renal aplasia, characterized by the absence of moderately bright signals of dorsal intensity with maternal fat (void signal) within the renal pelvis and bladder. Renal parenchymal signals are less intense than maternal fat and are not present in renal aplasia. The contribution of fetal MRI to the diagnosis of renal aplasia remains unknown. In one study, fetal MRI was helpful in indicating ectopic hypertrophy or horseshoe kidney when renal aplasia is suspected on ultrasonography
Differential diagnosis
A number of studies reported on risk factors in perinatal period [11-13] and perinatal outcomes [14-16]. True renal prolapse, severe renal hypoplasia, and cystic dysplasia with subsequent atrophy (renal dysplasia is defined as residual kidney and ureter without normal renal histology) leading to the disease clinically similar, but distinguishing these entities can be difficult both on ultrasound examination and at autopsy.
During unilateral renal aging, careful sonographic examination is needed to look for other structural anomalies, especially of the vertebrae, digestive system, heart, extremities, and genitourinary system, although many abnormalities are present. reproductive system difficult or impossible to detect. Prenatal ultrasound. Genetic testing by chromosome chip analysis (AMC) should be done before surgery. It is clear that CMA will provide additional karyotype information in about 6 to 7 percent of pregnancies where the fetus has an abnormality identified on ultrasound.
Diagnosis of unilateral renal agenesis is difficult because it relies accurately excluding the presence of a second kidney in ectopic location. Other anatomical abnormalities (particularly the reproductive tract) should be extensively evaluated during pregnancy with unilateral renal agenesis. If other abnormalities are detected, the risk of chromosomal abnormalities increases; amniocentesis should be provided to determine the fetal karyotype. There are no indications for premature fetuses. Other structural defects, copy number variants, single gene diseases, and chromosomal anomalies are all linked to renal agenesis.
Sonographic non-visualization of the foetal kidneys, ureters, and bladder, as well as oligohydramnios, are used to diagnose bilateral renal agenesis, which usually occurs after 16 weeks of pregnancy.
Most cases of bilateral renal agenesis are sporadic. Recurrence of bilateral renal agenesis is estimated to be 3 to 6%, although it might be as high as 8% in situations involving numerous congenital anomalies. Renal abnormalities affect 9 to 14% in relatives which are having first degree relations with patient having bilateral renal agenesis or dysgenesis. Given the heritability of these disorders, a renal ultrasonography evaluation is recommended for siblings and parents of infants born with dysgenesis or agenesis of both kidneys, or dysgenesis of the one and agenesis of other kidney. According to reports, patients with unilateral renal agenesis have a good prognosis and survival rates are similar to those of age- and gender-matched controls; however, indicate an increased risk of renal dysfunction, proteinuria, and hypertension, as well as a high risk of dialysis.
Given the heritability of these abnormalities, we recommend that parents and siblings of babies born with agenesis or dysgenesis of both kidneys, or agenesis of one kidney and dysgenesis of the other, have a renal ultrasonography evaluation.
Citation: Dighe O, Verma GP, Tayade S (2021) An Overview on Cannibalism: Signs and Symptoms, Diagnosis and Treatment. J Kidney 7:251. doi-10.35248/2472-1220.21.7.251
Received: 01-Nov-2021 Published: 29-Nov-2021
Copyright: © 2021 Dighe O, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
