Sonographic features of horseshoe kidney: review of 34 patients.

Abstract

Horseshoe kidney is a difficult sonographic diagnosis, especially if the isthmus is not seen. The purposes of this report are to review the sonographic images in 34 patients with proven horseshoe kidney, to discuss the limitations of ultrasonography in demonstrating the anomaly, and to identify features that would alert the examiner to the possibility of a horseshoe kidney. Among 34 patients, the isthmus was noted in 27. Of the 67 kidneys studied, 52 (78%) were judged to be low‐lying, and in 24 (36%) the sonographic images suggested malrotation with anteriorly pointing pelvis. Additional sonographic features seen in the 67 kidneys included a bent or curved configuration of the kidney in the long axis (58%), tapering and elongation of the lower pole (60%), and a poorly defined inferior border of the kidney (84%). These features should suggest the presence of a horseshoe kidney and direct the examiner to search for the isthmus.

Ultrasonographically detected renal fusion anomalies in Western Region of Nepal

“…USG is often the initial procedure performed in the workup of the patient(5). Bent or curved kidneys with tapering of the lower poles or indistinct lower pole margins in conjunction with an anteriorly oriented renal pelvis, low-lying kidneys and the presence of an isthmus are sonographic features of horseshoe kidney (3). Sonographic features of crossed fused ectopia are absence of kidney in contralateral renal fossa or pelvis and fused kidneys on the ipsilateral side with a characteristic anterior or posterior notch between the two fused kidneys and different orientations of collecting systems (8).…”

Horseshoe Kidney with Hydronephrosis – Tales of the Unexpected

“…It is observed in 1:400-600 live births, more frequently in men (male to female ratio approximately 2:1) [1,2,3]. HSK usually combines three distinct anomalies: renal ectopia, malrotation of the kidneys and renal vascular abnormalities [1].…”

“…The fused tissue is the isthmus and it prevents the kidneys from ascending and rotating due to the resistance it exerts as it reaches the inferior mesenteric artery. HSK may be associated with other urinary tract and extrarenal abnormalities, including stenosis of the ureteropelvic junction, double pelvis, abnormalities of the urinary bladder, supernumerary kidneys with horseshoe elements, undescended testis and hypospadias, septate vagina; skeletal, cardiovascular, gastrointestinal and central nervous system malformations, chromosomal abnormalities (including Patau and Gardner syndromes, Down and Turner syndromes) [1][2][3][4][5][6]. Moreover, HSK has been found even more frequently in autopsy examinations of children and infants, suggesting the high risk of mortality in young age, probably due to severe associated organ and/or chromosomal abnormalities [1].…”

“…Horseshoe kidney (HSK) is one of the most common inborn renal abnormalities, observed in 1:400-1:600 newborns [1,2,3]. It tends to have marked variability in the structure, position, blood supply and drainage of the fused kidneys.…”

Laparoscopic partial nephrectomy for renal cell carcinoma in a horseshoe kidney

“…While a third of patients are asymptomatic, renal calculi and ureteropelvic junction obstruction are common, leading to hydronephrosis. 5,6 In addition, a twofold risk of Wilms tumour has been described. 7 The association of renal tumours within a horseshoe kidney is extremely rare, with only 200 reported cases.…”