Hypertension in unilateral atrophic kidney secondary to ureteropelvic junction obstruction

Acute bilateral ureteropelvic junction obstruction as a rare cause of hypertensive crisis: a case report

Background

Bilateral ureteropelvic junction obstruction is a common cause of secondary hypertension in the pediatric population, often due to congenital malformation. On the other hand, it is less frequently encountered in the adult population and is usually due to an acquired condition, most commonly by a bilaterally obstructing nephrolithiasis causing hydronephrosis and subsequent hypertension. The aim of this study was to investigate and highlight the underlying mechanisms by which acute bilateral ureteropelvic junction obstruction causes hypertensive crisis and why early detection and prompt treatment are necessary to mitigate the effects of elevated blood pressure on target organs.

Case presentation

A 41-year-old African American man with hypertensive cardiomyopathy presented with anuria. He was found to have elevated blood pressure with evidence of target organ damage on laboratory examination, demonstrated by sudden elevation of his serum creatinine level. He was initially treated with oral and intravenous antihypertensives, with minimal improvement. The work-up was unremarkable apart from the imaging finding of acute bilateral ureteropelvic junction obstruction from obstructing nephrolithiasis causing hydronephrosis. Bilateral ureteral stents were placed for decompression, with resolution of the hypertensive crisis and improvement of renal function.

Conclusion

This case highlights the importance of prompt diagnosis and treatment of underlying acute bilateral ureteropelvic junction obstruction to mitigate the deleterious effects of sudden blood pressure elevation on target organs.

A 37-year-old male with unilateral hydronephrosis: A forgotten cause of secondary hypertension

The evaluation of Secondary hypertension is laborious, expensive and of low yield, though screening of reversible causes, is important to prevent target organ damage. Hypertension secondary to hydronephrosis is rarely described in clinical studies. We herein report a 37-year-old male with a history of resistant hypertension. Initial evaluation for a secondary cause of hypertension was negative. CT abdomen showed unilateral hydronephrosis (Right). After surgical correction, his blood pressure begins to normalize in 3 weeks with a reduction in antihypertensive drugs. The patient was off medications at 6 months of follow-up. The relief of obstruction was parallel to the normalization of blood pressure, which suggest a causal link between hydronephrosis and hypertension. Our case illustrates hydronephrosis as an important cause in the evaluation of hypertension.

Symptomatology and Clinic of Hydronephrosis Associated With Uretero Pelvic Junction Anomalies

The most common cause of hydronephrosis in the pediatric age group is ureteropelvic junction-type hydronephrosis (UPJHN). Since the advent of widespread maternal ultrasound screening, clinical presentation of hydronephrosis associated with UPJ anomalies has changed dramatically. Today most cases are diagnosed in the prenatal period, and neonates present without signs or symptoms. For those who are not detected at birth, UPJHN eventually presents throughout childhood and even adulthood with various symptoms. Clinical picture of UPJHN highly depends on the presence and severity of obstruction, and whether it affects single or both kidneys. Abdominal or flank pain, abdominal mass, hematuria, kidney stones, urinary tract infections (UTI), and gastrointestinal discomfort are the main symptoms of UPJHN in childhood. Other less common findings in such patients are growth retardation, anemia, and hypertension. UTI is a relatively rare condition in UPJHN cases, but it may occur as pyelonephritis. Vesicoureteric reflux should be kept in mind as a concomitant pathology in pediatric UPJHN that develop febrile UTI. Although many UPJHN cases are known to improve over time, close clinical observation is critical in order to avoid irreversible kidney damage. The most appropriate approach is to follow-up the patients considering the presence of symptoms, the severity of hydronephrosis and the decrease in kidney function and, if necessary, to decide on early surgical intervention.

Changes of arterial pressure following relief of obstruction in adults with hydronephrosis

BACKGROUND

As much as 20% of all cases of hypertension are associated with kidney malfunctions. We have previously demonstrated in animals and in pediatric patients that hydronephrosis causes hypertension, which was attenuated by surgical relief of the ureteropelvic junction (UPJ) obstruction. This retrospective cohort study aimed to investigate: (1) the proposed link between hydronephrosis, due to UPJ obstruction, and elevated arterial pressure in adults; and (2) if elevated blood pressure in patients with hydronephrosis might be another indication for surgery.

MATERIALS AND METHODS

Medical records of 212 patients undergoing surgical management of hydronephrosis, due to UPJ obstruction, between 2000 and 2016 were assessed. After excluding patients with confounding conditions and treatments, paired arterial pressures (i.e. before/after surgery) were compared in 49 patients (35 years old; 95% CI 29-39). Split renal function was evaluated by using mercaptoacetyltriglycine (MAG3) renography before surgical management of the hydronephrotic kidney.

RESULTS

Systolic (-11 mmHg; 95% CI 6-15 mmHg), diastolic (-8 mmHg; 95% CI 4-11 mmHg), and mean arterial (-9 mmHg; 95% CI 6-12) pressures were significantly reduced after relief of the obstruction (p < 0.001). Split renal function of the hydronephrotic kidney was 39% (95% CI 37-41). No correlations were found between MAG3 and blood pressure level before surgery or between MAG3 and the reduction of blood pressure after surgical management of the UPJ obstruction.

CONCLUSIONS

In adults with hydronephrosis, blood pressure was reduced following relief of the obstruction. Our findings suggest that elevated arterial pressure should be taken into account as an indication to surgically correct hydronephrosis.

Bilateral Obstructive Uropathy Caused by Congenital Bladder Diverticulum Presenting as Hypertensive Retinopathy

A congenital bladder diverticulum (CBD) is caused by inherent muscular weakness instead of obstruction of the bladder outlet. The major clinical conditions are recurrent urinary tract infection (UTI) and voiding dysfunction. This report describes a 15-year-old male adolescent who developed sudden visual disturbance resulting from hypertensive retinopathy. The cause of hypertension was bilateral obstructive uropathy caused by enlarged paraureteral bladder diverticula. After the non-functioning right kidney and ureter and the bilateral diverticula were removed, the left ureter was reimplanted in the bladder. Pathologic findings showed chronic pyelonephritis and partial loss of the bladder musculature in the diverticular wall. This observation indicates that dilated CBD can cause latent UTI, ureteral obstruction, hydronephrosis, and secondary hypertension.

The effect of alfuzosin on renal resistive index, urinary electrolytes and β2 microglobulin levels and TGF β-1 levels of kidney tissue in rats with unilateral ureteropelvic junction obstruction

BACKGROUND

In this study, it was aimed to determine the effects of alfuzosin on experimentally generated unilateral partial ureteropelvic junction obstruction (UPO) in rats.

MATERIALS AND METHODS

Thirty Long-Evans rats were randomly allocated into five groups. In control group (C), nothing was performed; in group Sham (S) only laparotomy was done; in Alfuzosin group (A) only alfuzosin was administered for two weeks (10 mg/kg/day p.o.) without any surgery; in UPO group, unilateral UP junction obstruction was produced; and in the Group UPT (ureteropelvic obstruction + treatment), alfuzosin was administered for two weeks (10 mg/kg/day p.o.) in addition to UPO production. Renal pelvic anteroposterior diameters were determined with ultrasonography (USG) and renal arterial resistivity indexes by color Doppler USG. Urine was collected both at the beginning and at the end of the experiment for 24 h in all the groups and at the end of the experiment, blood samples were obtained. Blood and urine electrolytes and TGF-β1, urine density, urine β2 microglobulin levels were determined. Renal tissue samples harvested from all of the rats were histopathologically evaluated. Results were determined using one-way ANOVA t-test; p < 0.05 was accepted as significant.

RESULTS

Urine density in the UPT group was lower with respect to UPO group and blood electrolytes were preserved as close to normal (p < 0.05). In the UPT group, urine TGF-β1 and blood TGF-β1, blood β2 microglobulin levels and histopathologic damage scores were lower compared to the UPO group (p < 0.05).

CONCLUSION

It is shown in this experimental unilateral partial UPO model that alfuzosin treatment prevents obstructive renal damage.

Hypertension and hydronephrosis: rapid resolution of high blood pressure following relief of bilateral ureteric obstruction

Hypertension secondary to hydronephrosis is not commonly reported in the medical literature. Tubuloglomerular feedback and the renin-angiotensin-aldosterone axis are thought to mediate this process. We describe a patient presenting with acute kidney injury and bilateral hydronephrosis secondary to pelvic malignancy in which peripheral venous renin and aldosterone were elevated. Her blood pressure improved rapidly following insertion of bilateral nephrostomies. The speed of resolution of hypertension following relief of obstruction suggests that humorally mediated vasoconstriction can play an important role in the mechanism by which hydronephrosis causes hypertension. We also discuss other causes of renal parenchymal compression that may lead to the development of hypertension.

Bilateral ureteropelvic junction obstruction presenting with hypertension and cerebral vascular accident

Cerebrovascular accident and renal hypertension secondary to ureteropelvic junction obstruction (UPJO) are extremely rare. A 6-year-old girl presented with intracranial hemorrhage because of hypertension secondary to the bilateral UPJO. This was successfully treated with craniotomy and subsequent percutaneous nephrostomy placement and bilateral pyeloplasty. Brain computerized tomography revealed right-sided intracranial hemorrhage, and renal ultrasonography confirmed bilateral severe hydronephrosis. Craniotomy with evacuation of intracerebral hematoma and bilateral nephrostomy under ultrasound guidance were performed. One week later, she underwent bilateral pyeloplasty in 2 stages. The patient has been well with normalized renal function and is completely cured of her hypertension in long-term follow-up.

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.