HYPERTENSION ASSOCIATED WITH MULTICYSTIC DYSPLASTIC KIDNEY IN CHILDREN

The Outcome of Multicystic Dysplastic Kidney Disease Patients at King Abdulaziz Medical City in Riyadh

Background Multicystic dysplastic kidney (MCDK) is a type of kidney dysplasia consisting of many irregular, various-sized cysts divided by dysplastic renal tissue, which negatively impacts kidney function. MCDK is one of the most common renal congenital disorders seen in antenatal ultrasounds. The typical prognosis of MCDK is complete or partial involution that starts antenatally and continues postnatally. The aim of the study was to shed light on the overall outcome of patients with MCDK. Methods We retrospectively collected data on MCDK patients from 2016 until 2022 at King Abdulaziz Medical City, Ministry of National Guard Health Affairs in Saudi Arabia, Riyadh. The data included the recording of epidemiological data, radiological and laboratory reports, and the presence of urological or non-urologically associated anomalies. Results A total of 57 patients with MCDK were reviewed. Seven of them were excluded due to the diagnosis of bilateral MCDK, which was incompatible with life. Of the remaining 50 patients, the right kidney was affected in 52% of them. Most patients were diagnosed antenatally (98%). The mean duration of follow-up for the study was 48 months. Vesicoureteral reflux (VUR) was detected in 22% of the total sample. Overall, 90% of the patients underwent kidney involution. A small percentage had genitourinary anomalies (20%), while a larger percentage (48%) had extrarenal abnormalities. Conclusion Multicystic dysplastic kidney disease is relatively common in children. The prognosis is affected by the presence of genitourinary and non-genitourinary anomalies. Patients have an overall good prognosis with conservative management. Antenatal screening, diagnosis, and long-term nephrological follow-up are essential for the optimal management of patients.

Nephrectomy improves both antihypertensive requirement and left ventricular mass for pediatric renal hypertension

BACKGROUND

Renal hypertension causes left ventricular (LV) hypertrophy leading to cardiomyopathy. Nephrectomy has been utilized to improve blood pressure and prepare for kidney transplantation in the pediatric population. We sought to investigate antihypertensive medication (AHM) requirement and LV mass in patients undergoing nephrectomy with renal hypertension.

METHODS

We performed a single institution retrospective review from 2009 to 2021 of children who have undergone nephrectomy for hypertension. Primary outcome was decrease in number of AHM. Secondary outcomes included change in LV mass and elimination of AHM. LV mass was measured using echocardiogram area-length and linear measurements. Non-parametric analyses were utilized to assess significance.

RESULTS

Thirty-one patients underwent nephrectomy. Median age was 12.5 years (0.8-19 years). Median of 3 AHM (range 1-5 medications) were used pre-operatively and patients had been managed for median 2.5 years. Twenty-nine had preoperative echocardiogram. Forty-eight percent of patients had LVH at nephrectomy. Median AHM after surgery was 1 (range 0-4 medications) at 30 days and 12 months, (p < 0.001). By 12 months after nephrectomy, 79.2% of patients had decreased the number of AHM. Eight (26%) patients were on no AHM 30 days after surgery, and 13 (43%) at 12 months. Systemic vascular disease and multicystic dysplastic kidney were the only factors associated with lack of improvement in AHM (p = 0.040). Fourteen patients had pre- and post-operative echocardiogram and 11 (79%) had improvement in LV mass (p = 0.016, 0.035).

CONCLUSIONS

Nephrectomy is effective in improving LV mass and reducing AHM for children with renal hypertension. Improvement is less likely in patients with systemic vascular disease and multicystic dysplastic kidneys. A higher resolution version of the Graphical abstract is available as Supplementary information.

Pathophysiological clinical features of an infant with hypertension secondary to multicystic dysplastic kidney: a case report

BACKGROUND

The association of hypertension with congenital renal hypoplasia has been established. We report a case of an infant who underwent nephrectomy for hypertension.

CASE PRESENTATION

Magnetic resonance imaging for the mother revealed fetal renal masses, and fetal multicystic dysplastic kidney was suspected. Following birth, the baby developed hypertension. Numerous investigations revealed that the left kidney was non-functional, and she was initiated on benazepril hydrochloride. However, because the drug response was poor, the left kidney was removed at the age of 7 months. Examination of the renal specimen revealed abrupt transition from normal to atrophic cortex with lobar atrophy and cysts. Tubular atrophy, marked abnormal blood vessels with wall thickening, gathered immature glomeruli, and parenchymal destruction were observed. Renin was partially localized in the proximal tubules and the parietal epithelium of the Bowman's capsule in the immature glomeruli. We speculated that an abnormal vascular structure and irregular renin localizations may be the cause of hypertension. Serum renin and aldosterone levels gradually reduced post-surgery, reaching normal levels on the 90th postoperative day. A long follow-up is needed due to the possibility of the child developing hypertension in the future.

CONCLUSION

This is a case of an infant with MCDK, which discusses the clinicopathological features based on the pathophysiological analysis, including renin evaluation.

The efficacy of unilateral laparoscopic nephrectomy in the pediatric hypertensive patient

BACKGROUND

Secondary hypertension due to a poorly functioning or non-functional kidney may be refractory to medical management. In such cases, nephrectomy can improve or cure hypertension. With the routine use of laparoscopy, nephrectomy can be performed in a minimally invasive manner, but surgery still carries inherent risks and complications.

OBJECTIVE

The objective of this study is to evaluate the outcomes of laparoscopic nephrectomy performed for secondary hypertension and identify potential predictors of postoperative hypertension resolution.

METHODS

After obtaining approval from institutional review board, patients from January 2002 to March 2018 who underwent laparoscopic nephrectomy were identified using Current Procedural Technology codes. All charts were then manually reviewed to isolate those patients with secondary hypertension present preoperatively. Patient demographics, urologic history, and laboratory and imaging findings were recorded for all patients. Serial blood pressures were recorded at all renal visits along with any antihypertensive medication changes. Postoperative outcomes and complications were also noted for all patients.

RESULTS

A total of 20 patients (7 girls, 13 boys) underwent laparoscopic nephrectomy to treat hypertension at an average age of 10.6 years (range 1.7-17.0 years). Etiology of a solitary non-functional kidney was vesicoureteral reflux in 10 of 20 patients, multicystic dysplastic kidney in 5 of 20, ureteropelvic junction obstruction in 2 of 20, ureteral obstruction in 1 of 20, and renal artery stenosis in 2 of 20 patients. At time of surgery, 3 of 20 patients were on two antihypertensives, 10 of 20 were on one antihypertensive, and 7 of 20 proceeded to surgery with no medical management. In the 30-day postoperative period, no complications were noted. Hypertension improved in 10 of 20 (50%) patients, all of whom were not on any antihypertensive medications after surgery. Hypertension persisted in 4 of 20 (20%) patients, requiring the same antihypertensive regimen and worsened in 6 of 20 (30%) patients, requiring increased doses and/or additional antihypertensives. Average follow-up time was 2.7 years. No significant predictors of postoperative hypertension result were identified when comparing the groups of responders and non-responders.

DISCUSSION

While laparoscopic nephrectomy for a non-functioning kidney in the setting of hypertension is a safe procedure, the cure rate for hypertension in the cohort appears to be on the low side of what was previously reported. While the small sample size is a main limitation, it is among the largest sample sizes for pediatric hypertensive patients. Previously shown predictors were not predictive in the similar-sized cohort.

CONCLUSIONS

Patients should be carefully counseled on the risks and benefits of nephrectomy to treat hypertension, the importance of continued follow-up after nephrectomy, and the possible need for chronic medical management with antihypertensives.

Evidence-based treatment of multicystic dysplastic kidney: a systematic review

OBJECTIVES

There is a lack of a standardised protocol for the investigation and non-operative management of paediatric multicystic dysplastic kidney (MCDK). Institutional protocols for non-operative management remain essentially ad hoc. The primary outcome of this systematic review is to establish the incidence of hypertension associated with an MCDK. The secondary outcome is to determine the malignancy risk associated with an MCDK. The tertiary outcome is to assess the rate of MCDK involution. Subsequent to these, an evidence-based algorithm for follow-up is described.

METHODOLOGY

A systematic review of all relevant studies published between 1968 and April 2017 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified by specific inclusion and exclusion criteria, all of which included data relevant to the primary, secondary and tertiary outcomes. Hypertension was defined as systolic blood pressure greater than the 95th centile for gender, age and height centile. Subset analysis was performed for hypertension associated with an MCDK.

RESULTS

The primary outcome measure revealed a 3.2% (27/838) risk of developing hypertension associated with an MCDK. The secondary outcome measure noted a 0.07% malignancy risk (2/2820). The tertiary outcome measure established that 53.3% (1502/2820) had evidence of involution of the dysplastic kidney. A total of 44 cohort studies (2820 patients) were analysed.

CONCLUSION

Given the low risk of hypertension and malignancy, which is similar to the general population, the current conservative non-operative pathway is an appropriate management strategy. An algorithm to help support clinicians with ongoing management is proposed.

Outcome of Multi-Cystic Dysplastic Kidneys in Children

Background:

Renal cystic diseases are important causes of chronic kidney disease (CKD).

Objectives:

We report the pattern of renal cystic disease in children and evaluate the outcome of children with multicystic dysplastic kidney (MCDK).

Patients and Methods:

Retrospective study of all children with cystic kidney diseases at King Abdulaziz University hospital from 2006 to 2014.

Results:

Total of 55 children (30 males); 25 MCDK, 22 polycystic kidney diseases (PKD), 4 nephronophthises and 4 renal cysts. Consanguinity was positive in 96.2%. MCDK and simple renal cyst patients had good renal function while PKD and nephronophthisis developed renal impairment. Most MCKD were diagnosed ante-natally, 16 of them were followed up for 3.4 (1.97) year. Their last creatinine was 33.9 (13.5) umol/L. MCDK was spontaneously involuted at mean age of 2.6 (1.3) years in 56%.

Conclusions:

MCDK is the commonest cystic renal disease and diagnosed ante-natally in the majority of cases. It has a good prognosis.

Multicystic dysplastic kidney: Impact of imaging modality selection on the initial management and prognosis

OBJECTIVE

To evaluate the impact of imaging modalities on the evaluation and prognosis of children with multicystic dysplastic kidney (MCDK) disease.

PATIENTS AND METHODS

A retrospective analysis of all children with MCDK diagnosed from 2004 until 2012 was performed. The study included 63 patients for whom all postnatal imaging modalities were available: renal bladder ultrasound (RBUS), dimercaptosuccinic acid scan (DMSA) and voiding cystourethrogram (VCUG). Cases with major congenital abnormalities or incomplete data were excluded. Abnormalities in the contralateral kidney and the fate of MCDK were also addressed.

RESULTS

At diagnosis, the average age was four-and-a-half months. The majority of cases were detected antenatally (87%). Postnatal RBUS and DMSA scans established the diagnosis of MCDK in 92% and 98% of patients, respectively. DMSA showed photopenic areas in the contralateral kidneys in 10% of patients; all of them had hydronephrosis and were confirmed to have vesicoureteral reflux (VUR). Contralateral VUR was detected in 16 patients; 63% of them had hydronephrosis. After a mean follow-up of three-and-a-half years, involution occurred in 62% of patients and the involution rate was inversely proportional to the initial size.

CONCLUSIONS

The classical appearance of MCDK on RBUS was sufficient to establish the diagnosis in most patients. DMSA scan was more accurate in confirming the diagnosis and evaluating the contralateral kidney. Selective screening for VUR in patients with contralateral hydronephrotic kidney should be considered.

Nephrectomy for hypertension in pediatric patients with a unilateral poorly functioning kidney: a contemporary cohort

PURPOSE

A unilateral poorly or non-functioning kidney is a cause of hypertension in children. We report the outcomes of pediatric patients with unilateral renal parenchymal disease who underwent nephrectomy for hypertension.

MATERIALS AND METHODS

Consecutive hypertensive children undergoing nephrectomy with a unilateral poorly or non-functioning kidney were retrospectively reviewed; preoperative and postoperative clinical variables were analyzed.

RESULTS

From July 2002 to August 2009, 21 patients (8M:13F) with average age 3.5 years and average follow-up 17.8 months were studied. Eleven patients had multicystic dysplastic kidney, 8 had reflux nephropathy, and 2 had ureteropelvic junction obstruction. Fourteen of 21 (67%) had blood pressure normalization after nephrectomy. Seven of 11 with MCDK were normotensive postoperatively compared to 6/8 patients with reflux nephropathy, and 1/2 patients with UPJ obstruction. Of the 14 patients normotensive postoperatively, 7 were on antihypertensives prior to surgery. Four of 7 patients stopped their anti-hypertensive medications postoperatively, 2 decreased from 3 and 4 medications to 1, and 1 remained on an ACE inhibitor. There were 2 patients with contralateral renal scarring, both of which remained hypertensive postoperatively.

CONCLUSIONS

Nephrectomy in hypertensive pediatric patients with a unilateral poorly functioning or non-functioning kidney yielded hypertension resolution in 67% (14/21), permitting cessation or diminution of antihypertensives in many patients. Given the alternative of lifelong antihypertensives with the risk of medication non-compliance and side-effects, nephrectomy is a logical option of care which can be offered to patients and families with informed knowledge of the potential for cure.

Is the risk of hypertension an indication for prophylactic nephrectomy in patients with unilateral multicystic dysplastic kidney?

OBJECTIVE

Surgery is still proposed by some as the treatment of choice for unilateral multicystic dysplastic kidney (UMCDK) because of the potential complications of hypertension, infection and malignant change. The purpose of this study is to demonstrate that the risk of hypertension does not justify routine nephrectomy.

MATERIAL AND METHODS

We report 41 cases of UMCDK, treated between 1980 and 2001, 28 of whom were male (68%). Twenty-one patients were nephrectomized (51%). Twenty patients (49%) underwent clinical and ultrasound follow-up. Blood pressure was controlled every 3-4 months (over a period ranging from 9 months to 6 years) and an ultrasound scan was performed every 6 months during the first 2 years, and annually thereafter.

RESULTS

In the patients treated non-operatively we observed a progressive spontaneous involution of their multicystic dysplastic kidneys and the total absence of complications such as hypertension or malignancy.

CONCLUSION

It is reasonable to conservatively manage patients with UMCDK by means of repeated ultrasound examinations and blood pressure control.

Management and etiology of the unilateral multicystic dysplastic kidney: a review

In children, unilateral multicystic dysplastic kidney (MCDK) is one of the most frequently identified urinary tract abnormalities. A variety of proposed etiologies has been associated with the underlying pathogenesis of MCDK. These include genetic disturbances, teratogens, in utero infections, and urinary outflow tract obstruction. From 5-43% of the time, MCDK has associated genito-urinary anomalies, both structural and functional in nature. A review of the literature reveals that involution rates are reported to be 19-73%, compensatory hypertrophy of the contralateral kidney occurs from 24-81% of the time, and estimated glomerular filtration rates (GFRs) (by the Schwartz formula) range from 86-122 ml/min per 1.73 m(2) body surface area. Most authors suggest serial ultrasonography to monitor contralateral growth, routine blood pressure monitoring, and a serum creatinine monitoring algorithm. The risk of hypertension in those with MCDKs does not appear to be greater than that of the general population, and the rates of malignant transformation of MCDK are small, if at all increased, in comparison with those in the general population. If the patient develops a urinary tract infection or has abnormalities of the contralateral kidney, shown on ultrasound, a voiding cystourethrogram is recommended. Finally, the body of literature does not support the routine surgical removal of MCDKs.

Segmental multicystic dysplasia and ureteropelvic junction obstruction in a nonduplicated kidney

A 2-month-old child presented for evaluation of prenatal hydronephrosis. Imaging studies were consistent with a right duplex system with a dysplastic, nonfunctioning upper pole and lower pole ureteropelvic junction obstruction. We proceeded with removal of the upper pole and pyeloplasty and were surprised to find a single collecting system with a cystic, dysplastic upper pole segment and the absence of an upper pole pelvis or ureter. The rare diagnosis of a segmental multicystic dysplastic kidney with ipsilateral ureteropelvic junction obstruction was made. We present a review of the case and of previous literature on this topic.

Cross-fused ectopic multicystic dysplastic kidney with associated ureterocele

We describe a case of the unique congenital anomaly of cross-fused ectopic multicystic dysplastic kidney with associated ureterocele and demonstrate the usefulness of magnetic resonance imaging in fetal imaging.

PEDIATRIC UROLOGICAL CAUSES OF HYPERTENSION

PURPOSE

We reviewed the association of hypertension with several common pediatric urological conditions.

MATERIALS AND METHODS

We comprehensively reviewed the published literature linking hypertension with urinary tract infection, renal scarring, vesicoureteral reflux, multicystic dysplastic kidney, ureteropelvic junction obstruction and posterior urethral valves.

RESULTS

Hypertension is a recognized sequela of several common pediatric urological conditions. It is thought to be a direct consequence of renal damage or scarring often resulting from vesicoureteral reflux and/or febrile urinary tract infection. Multicystic dysplastic kidney has rarely been shown to cause hypertension when examined in large series rather than as isolated case reports. Ureteropelvic junction obstruction and posterior urethral valves have been linked to hypertension, although to our knowledge no series to date has specifically examined this relationship and smaller retrospective reviews seldom describe associated hypertension.

CONCLUSIONS

Several pediatric urological conditions are known to cause hypertension. However, methodological flaws in the literature, including a lack of standardized blood pressure followup, highly variable patient populations and poor control of concomitant urological abnormalities, greatly limit the ability to establish a causative link between any 1 specific condition and hypertension. Early diagnosis, the prevention of infection, close clinical followup and early intervention remain the primary means of preventing pediatric urological causes of hypertension.

Nephrectomy for multicystic dysplastic kidney: if and when?

OBJECTIVES

To evaluate the criteria for conservative versus surgical treatment of multicystic dysplastic kidneys and to attempt to specify the optimal timing for surgery, when considered indicated.

METHODS

The study population comprised 48 antenatally or neonatally detected consecutive patients with unilateral multicystic dysplastic kidney. The fate of the affected renal conglomerate was regularly analyzed by ultrasonography. All cases were primarily followed up conservatively. In the patients who eventually underwent nephrectomy, the decision to operate was made after a minimum of 18 months (median 25).

RESULTS

Ultrasound follow-up showed complete involution in 13 cases (27%); in 35 cases (73%), the renal conglomerate persisted throughout the study period (mean 46 months). Of the 48 patients, 32 (67%) eventually underwent nephrectomy. The size of the affected mass among the involuted cases was significantly smaller throughout the study period than in those requiring nephrectomy. The difference between the two groups continuously increased during follow-up, with a mean involution rate of 2.5 cm/yr versus 0.6 cm/yr (up to 18 months) for the involuted versus noninvoluted cases, respectively (P <0.0001). From 18 months on, no statistically significant involution was observed in those who eventually underwent nephrectomy.

CONCLUSIONS

Patients with antenatally or neonatally detected multicystic dysplastic kidney can primarily be followed up conservatively. Involution occurs in approximately one fourth of the cases, usually within about 14 months. In our experience, no significant involution can be expected to occur after 18 months. If surgery is decided on, we recommend an age of about 2 years. Late complications (eg, Wilms' tumor and renovascular hypertension) are rare.

Pediatric hypertension: recent literature

This article reviews selected recent literature specifically concerning pediatric hypertension, much of which has focused on measurement and monitoring of blood pressure, as well as on evaluating antihypertensive medications. Normative data for blood pressure in children have been widely available for some time, based upon seated in-office measurements. In recent years, ambulatory blood pressure monitoring (ABPM), facilitated by user-friendly instrumentation, has become more commonplace, though norms are not based on large populations. However, ABPM has important uses in assessing blood pressure as well as in monitoring antihypertensive. This review discusses issues involved in determining blood pressure, as well as the utility of ABPM in several situations. Recent developments concerning pediatric antihypertensive therapy are considered, as well as new information relevant to the diagnosis, course and treatment of hypertension in children and adolescents.