KIDNEY ANOMALIES: HORSE SHOE KIDNEY

Abstract

Hemalatha Devi1, Komarabattina Rattaiah2, R. Nageshwar Rao3, Kotikala Prabhakara Rao4

INTRODUCTION: Horse Shoe Kidney was first recognized during an autopsy by De Carpi in 1521. This anomaly consists of two distinct renal masses lying vertically on either side of the midline and connected at their respective lower poles by a parenchymatous or fibrous isthmus that crosses the mid plane of the body. This isthmus lies at the level of 4th lumbar vertebra just beneath the origin of inferior mesenteric artery in about 40% of cases. Fusion of upper poles instead of the lower poles results in an inverted horse Shoe Kidney which constitute 5-10% of ail Horse-Shoe kidneys, (i.e. in 95% of HSK, fusion is at lower poles). HSK is found more commonly in males by a 2:1 margin.

AIM OF STUDY: An attempt has been made to know the various anomalies. The study has been taken up with the fond hope of helping the clinician, sonologist, and surgeons during their routine work. To apply this knowledge to the incoming post graduates in their research works.

EMBRIOLOGICAL BASIS & KDNEY: The abnormality originates between 4th and 6th weeks of gestation, after the ureteral bud has entered the renal blastema. Boyden (1931) postulated that at the 14mm stage (4.5 weeks) the developing metanephric masses lie close to one another, any disturbance in their relationship may result in joining at their inferior poles. A slight alteration in the position of the umbilical or common iliac artery could change the orientation of migrating kidneys thus leading to contact and fusion. In 1941 Dees (Nation 1945, Bell 1946, Gleen 1959, Campbell 1970) described horse-shoe kidney disease occurrence in 0.25% of the population or about 1 in 400.

OBSERVATION: In the present study 176 specimens of kidneys were studied out of which 40 were fetal specimens and the rest were adult specimens consisting of both cadaveric and sonograms. The adult specimens from cadavers were 76 and 60 from sonograms.

MATERIAL & METHODS: Abdomen is opened; superficial viscera and coils of intestine removed to get a clear view of posterior abdominal organs and anomalies are noted

SUMMARY & CONCLUSION: The abnormality originates between 4th and 6th weeks of gestation, after the ureteral bud has entered the renal blastema. Boyden (1931) postulated that at the 14mm stage (4.5weeks) the developing metanephric masses lie close to one another, any disturbance in their relationship may result in joining at their inferior poles. Usually the fusion of the both kidneys occurs before they have rotated on their long axis, thus pelvis and ureters of HSK are being usually placed anteriorly. Rarely, fusion occurs after some rotation had already taken place in which case the pelves are anterimedialy placed.

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